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Physics Physics

physics Watch Physics

Friday 17 July

Optics

Optical Control of Chirality by Ultrafast Symmetry Breaking in Membrane Metasurfaces

Nikita Glebov, Alena Mamonova, Olesia Pashina et al. (+7 more)

Chirality underpins a wide range of light-matter interactions, yet methods for its dynamic control in photonic systems remain limited. Here, we demonstrate ultrafast all-optical control of chirality in silicon metasurfaces through transient symmetry breaking. Our approach exploits photonic eigenstates of opposite spatial parity engineered to be highly susceptible to symmetry perturbations. Optical excitation generates free carriers that establish a transient refractive-index gradient across the membrane thickness, breaking out-of-plane mirror symmetry and facilitating hybridization of the parity-opposite modes into chiral photonic states. This enables the reversible creation and modulation of chirality on a 10-100 ps timescale, manifested by pronounced changes in the metasurface circular dichroism. By dynamically reconfiguring a fundamental symmetry property of the photonic structure rather than merely its optical response, our work establishes a route towards ultrafast control of chiral light-matter interactions and opens opportunities for active nanophotonic and information processing technologies.
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All authors Nikita Glebov, Alena Mamonova, Olesia Pashina, Felix Ulrich Brikh, Aleksei Ezerskii, Sergey V. Makarov, Mihail Petrov, Maxim Gorkunov, Ivan Sinev, Hatice Altug

Atomic Physics

Collinear Laser Spectroscopy on a Fast Atomic Beam of Boron Generated by Photodetachment of Accelerated B- Ions

L. Renth, P. Imgram, B. Maass et al. (+6 more)

Atomic beams for collinear laser spectroscopy are typically produced via charge exchange reactions in an in-beam vapor cell. This process is accompanied by the formation of a considerable amount of longer-lived excited state population, which is not accessible for spectroscopy and also induces fluorescence background to photon detectors. We present an alternative method to produce an atomic beam, consisting exclusively of ground-state atoms. Negative ions are neutralized in-flight by photodetachment and are subsequently used for fluorescence spectroscopy. As a test candidate, a negative boron ion beam was produced in a cesium sputtering source and superimposed with a co-propagating high-power pulsed infrared laser. The neutral atoms were subsequently excited along the $2s^2 2p\,{}^{2\!}P_{1/2,3/2} \rightarrow 2s^2 3s\,{}^{2\!}S_{1/2}$ transitions by a continuous-wave laser at about 250 nm. The statistics and efficiency were limited by the combination of a continuous ion beam with a low-repetition-rate laser, but a clear route for the improvement combining existing techniques is presented, which can then be applied to other elements as well as negative molecular ions.
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All authors L. Renth, P. Imgram, B. Maass, D. Hanstorp, J. Krämer, D. Koestel, D. Lu, W. Nörtershäuser, T. Walther

Data Analysis and Statistics · Cross-listed from cs.SI

Growing Hypergraphs with Homophily

Violet Ross, Francis Cataldo and Philip S. Chodrow

There are many extant models of hypergraphs with interactions governed by attribute-based homophily between nodes, but most assume independence between edges conditional on node parameters. Relaxing this assumption, we study a mechanistic model of growing hypergraphs in which edge formation is influenced by both previous edges and binary node labels. Edges form in this model as noisy copies of previous edges, where the transmission of nodes from one edge to the next depends on multiple homophilic mechanisms between labels. These homophilic mechanisms give rise to tunable assortative structure in the hypergraph. We derive a power law for the degree distribution in this model and describe the long-term dynamics of the joint distribution of labels contained in edges. Our model defines a likelihood over a labeled hypergraph, allowing us to use standard maximum-likelihood techniques to structure algorithms. We estimate the model parameters on synthetic and real data via (stochastic) expectation maximization. These estimates give statistically-principled descriptions of the operation of homophily in empirical polyadic systems. We also demonstrate an approach to community detection via simulated annealing which, though computationally expensive, achieves competitive results on both synthetic data and certain empirical data sets known to be challenging to community detection techniques based on the edge-independence assumption. Our findings highlight the benefits of incorporating edge- and label-dependence in higher-order modeling and data analysis, and point to several directions for future work.
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Data Analysis and Statistics · Cross-listed from stat.ME

Dynamic models with $p$ parameters are identified by $2p+1$ random features

Michael Wieck-Sosa and Cosma Rohilla Shalizi

A foundational principle in nonlinear dynamics is that the structure of a dynamical system can be recovered from a small number of generic measurements or coordinates. We develop an analogous principle for the identification of dynamic models for time series with noise, which builds on previous identification results for noiseless dynamical systems. The noise is allowed to be non-iid, non-Gaussian, and dependent on the state. Our results cover noisily observed differential equations and discrete-time dynamical systems, as well as stochastic models with process noise. We illustrate the utility of this identification principle using a Lorenz-63 model and a Hénon map model, both with observational noise.
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Medical Physics

Fast ungated five-dimensional cardiac MRI on a 1.5 T MR-linac for MRI-guided radiotherapy

M.L. Terpstra, T.E. Olausson, M.M.N. Aubert et al. (+4 more)

Background: Stereotactic arrhythmia radio-ablation (STAR) for patients with ventricular tachycardia is currently limited by complex cardiorespiratory motion. Current 5D-MRI motion models require long acquisition and reconstruction times, limiting clinical viability. Objective: To develop a fast, ungated 5D-MRI reconstruction method for personalized motion characterization to support MRI-guided STAR treatments. Methods: We propose a fast, ungated 5D-MRI reconstruction method based on the CMR-MOTUS framework. The method uses a 3D Cartesian acquisition with a joint optimization framework to reconstruct a motion-corrected reference image and low-rank deformation vector fields (DVFs). By exploiting the low rank structure, we explicitly disentangle respiratory and cardiac motion during optimization. Then, the DVFs are used for 5D-MRI reconstruction with a retrospectively adjustable number of motion states. Validation was performed using digital and physical cardiorespiratory phantoms. Furthermore, the approach was evaluated using 10 healthy volunteers, comparing motion consistency with 2D cine MRI. Results: Validation of 5D CMR-MOTUS using digital and physical phantoms demonstrated accurate 5D-MRI reconstruction. In the physical phantom, 5D CMR-MOTUS achieved a left-ventricle DICE of 0.96 +/- 0.01. In the volunteer cohort, the 5D-MRI scans showed strong motion to 2D cine MRI, with a cardiac motion error of 0.1 +/- 0.9 mm and a respiratory motion error of 0.2 +/- 2.9 mm. Crucially, 5D-MRI data were acquired in 1 minute and reconstructed in 6 minutes. Conclusions: The proposed 5D-MRI method enables rapid, high-quality, and personalized motion characterization, demonstrating potential for integration into MRI-guided STAR treatments. Data Availability: The 3D k-space data and 5D reconstructions for the ten volunteers are publicly available at https://doi.org/10.5281/zenodo.21278894
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All authors M.L. Terpstra, T.E. Olausson, M.M.N. Aubert, C. Beijst, A. Sbrizzi, C.A.T. van den Berg, M.F. Fast

Atomic Physics

One-loop self-energy using a numerical Green function

Hugo D. Nogueira, Maen Salman and Jean-Philippe Karr

We calculate the one-loop self-energy in hydrogenlike atoms using a numerical Green function obtained by solving the radial Dirac equation in an exponential basis set. The self-energy correction in the ground state of hydrogenlike uranium is obtained with about $10^{-5}$ relative uncertainty in the Feynman gauge. Using a convergence acceleration scheme, we extend our calculations to the region of low nuclear charges. Our results allow calculating the self-energy correction for the hydrogen atom with $10^{-4}$ relative uncertainty. Calculations in the Coulomb gauge are also presented, improving the precision to $10^{-5}$. Present limitations and possible improvements of our method are discussed.
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Fluid Dynamics · Cross-listed from cond-mat.mes-hall

Negative quantum friction in nanoscale water flows: the Wigner picture

Adriano Tiribocchi, Marco Lauricella, Efthimios Kaxiras et al. (+1 more)

We explore the phenomenon of "quantum" friction based on a single-particle model patterned after the Wigner equation describing electrons flow in a solid wall confining nanoscale water flows. The numerical simulations show a clear signature of negative quantum friction, namely a net momentum transfer from the electrons in the solid wall to the flowing water molecules. Such net momentum transfer results into a sizeable reduction of the water friction, up to forty percent, depending on the strength of the coupling between classical and quantum fluctuations. Our results offer the prospect of a theoretical framework bridging classical and quantum description by using continuum kinetic theories and particle-based simulations.
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All authors Adriano Tiribocchi, Marco Lauricella, Efthimios Kaxiras, Sauro Succi

Physics and Society

Diffusion-induced instabilities promote cooperation in eco-evolutionary networks

Sourav Roy, Md Sayeed Anwar, Timoteo Carletti et al. (+2 more)

Understanding how cooperation persists despite the advantage of selfish behavior remains a central challenge in evolutionary dynamics. Classical models of public goods dilemmas predict dominance of defectors, yet natural and social systems often sustain cooperation. We study an eco-evolutionary public goods game on complex networks where cooperators and defectors diffuse at different rates. When the isolated system is in a defector-dominated coexistence regime, faster dispersal of defectors than cooperators leads to a symmetry-breaking transition that produces localized clusters of cooperators. In heterogeneous networks, nodes with higher connectivity become significantly more likely to exhibit cooperative dominance. A degree-based mean-field reduction supports this result by showing that network connectivity controls an effective coupling strength proportional to node degree, thereby producing a bifurcation that separates defector-dominated and cooperative states. We also address why not all hubs become cooperative by means of a multistability analysis. These results reveal how asymmetric mobility and heterogeneous connectivity jointly promote cooperation in structured populations.
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All authors Sourav Roy, Md Sayeed Anwar, Timoteo Carletti, Matjaz Perc, Dibakar Ghosh

Atomic Physics

A coherent quantum interface between a neutral atom and a polar molecule

Daniel K. Ruttley, Tom R. Hepworth, Juan M. García-Garrido et al. (+4 more)

Arrays of trapped neutral atoms and polar molecules have separately emerged as powerful and complementary platforms for quantum science. Neutral atoms enable fast, programmable interactions through excitation to Rydberg states, whereas polar molecules possess long-lived rotational states that are attractive for quantum memories and qudits. Combining these platforms would create new possibilities, but requires a coherent interface between individual atoms and molecules, which so far has not been realised. Here, we establish such an interface between a single neutral atom and a single polar molecule. By tuning atomic and molecular transitions into resonance, we realise strong state-dependent dipolar interactions at micrometre separations in an optical tweezer platform with single-particle control. We exploit this interface to perform quantum operations between the two particles, demonstrating atom-mediated readout of a molecular qubit, coherent spin exchange, and entanglement using a blockade-based controlled-NOT operation. These results establish a new hybrid quantum platform at the intersection of atomic and molecular physics, in which long-lived molecular quantum information can be rapidly mapped onto an atom for readout or onward coherent transfer. The platform provides a route to hybrid quantum processors utilising atom-mediated readout and entanglement of molecular qubits, mixed-species quantum simulators of dipolar systems, and macroscopic entangled molecular states for quantum-enhanced metrology and precision sensing.
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All authors Daniel K. Ruttley, Tom R. Hepworth, Juan M. García-Garrido, Caleb J. H. Rich, Rosario González-Férez, Alexander Guttridge, Simon L. Cornish

Biological Physics · Cross-listed from q-bio.CB

A phenomenological multiscale framework for orientational interactions and viscoelasticity in migrating epithelial monolayers

Ivana Pajic-Lijakovic, Milan Milivojevic and Peter V.E. McClintock

Collective migration of epithelial monolayers emerges from the interplay between mechanical interactions and biochemical signalling. Here, we present a phenomenological mechanobiological framework linking cell-scale orientational interactions to tissue-scale mechanics. We distinguish reversible and irreversible head-on and glancing collisions, showing that reversible interactions store orientational mechanical energy while preserving collision geometry, whereas irreversible interactions dissipate energy and alter cell orientation. The balance between energy storage and dissipation governs collective migration, mechanical feedback, and density-dependent processes including cell jamming and live cell extrusion. These interactions regulate cell elasticity, contractility, and adhesion, thereby modifying epithelial surface tension and the effective viscoelastic response of the monolayer. We quantify these effects using orientational interaction potentials, an effective second virial coefficient, and dimensionless measures of stored and dissipated orientational energy. The relative contribution of these mechanisms increases with cell packing density, becoming dominant near the jamming transition. This framework provides a constitutive interpretation connecting collision-induced orientation dynamics with emergent epithelial rheology and suggests how density-dependent interaction regimes shape collective migration and tissue viscoelasticity.
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Physics and Society

Sociocultural Influences on Opinion Formation: Word of Mouth Dynamics, Mass Media and Behavioural Development

Elpida Tzafestas

We study a society of agents belonging to a number of occupational or cultural groups that form opinions about others' situation in the same or different group. Opinions develop either by observation within own group or by directly interacting with members of other groups, therefore by word of mouth (WoM). Additionally, global mass media (MM) may be available that inform indirectly about the situation of the various groups. The sociocultural interplay of these processes and the degrees of relative exposure to each of the sources has diversified effects on final opinion and social attitude formation. In large and complex societies and groups where not everyone can physically interact by WoM with everyone about everything, these processes show potential for mass control and social automation engineering. Our model can also represent and be generally informative about segmented societies that consist of groups with different occupational and cultural characteristics and it can offer insights into social issues such as the generation gap, social cleavages and so on.
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Biological Physics

Cauchy-Paul wavelet transforms revisited: A framework for intermittent non-sinusoidal oscillations

P. Argoul, J. Taillard and F. Argoul

This paper revisits the continuous wavelet transform framework by establishing a rigorous physical and dimensional formulation of the Cauchy-Paul mother wavelet, tailored specifically for intermittent, non-sinusoidal electrophysiological oscillations. Departing from conventional, purely mathematical definitions, we introduce a characteristic time scale $\tau$ into the frequency-domain formulation of the mother wavelet. This parameter ensures strict dimensional consistency by maintaining dimensionless functional arguments, thereby confining the physical dimension solely to the multiplicative normalization constant under both $L^1(\mathbb{R})$ and $L^2(\mathbb{R})$ norms. A sharp dimensional and structural analysis of the resulting wavelet is conducted. We demonstrate that the spectral asymmetry inherent to the Cauchy-Paul wavelet dictates a strict mathematical hierarchy between three alternative reference frequencies: the peak ($L^\infty$), the centroid ($L^1$), and the energy-weighted ($L^2$) frequencies. Each frequency definition yields distinct quality factors ($Q$) and time-bandwidth characteristics that govern the time-frequency localization trade-off. To track multi-component EEG sleep pattern signals, a phase-based algebraic estimator is deployed alongside an advanced ridge-extraction method. The robust tracking performance and morphological adaptability of the proposed Cauchy-Paul framework are first numerically validated on synthetic transients, harmonics, and chirps, and subsequently applied to real, non-stationary EEG recordings to successfully isolate and decipher the non-sinusoidal signatures of sleep spindles.
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Instrumentation and Detectors

A Hydrogenated Amorphous Silicon Photodiode indirect flexible device for radiation flux measurements at low intensities

Mauro Menichelli, Aishah Bashiri, Marco Bizzarri et al. (+46 more)

The objective of the Photo-HASPIDE experiment is the construction and test of an indirect a-Si:H (Hydrogenated Amorphous Silicon) photo-detector plus scintillator device on a flexible substrate for the detection and measurement of particles fluxes (X-rays, electrons and protons) and for dosimetric measurements. The idea behind this experimental project lies in the utilization of Hydrogenated Amorphous Silicon (a-Si:H) as photodiode material; owing to its notable attributes of radiation hardness, light detection capability and mechanical flexibility. After the implementation of the HASPIDE experiment, which explored direct radiation detection using a-Si:H devices on a polyimide (PI) substrate, we aim to delve into indirect detection by employing these devices in conjunction with flexible and rad-hard scintillators like polysiloxane. The indirect detector design holds promise for improved responsiveness to low radiation fluxes compared to direct detection methods. The indirect a-Si:H detector should be composed of arrays of small (about 5 x 5 mm2) scintillator crystals read by a-Si:H photodiodes. Through optimization of the scintillator and detector thicknesses, we expect to achieve a better performance for low minimum detectable fluxes compared to direct detection methodologies. This new detector will find application in in-vivo dosimetry during radiotherapy or hadron-therapy and also, due to its expected fast response, in FLASH therapy. Another important application will be also in Solar Physics using these devices to measure particle fluxes in solar energetic particle events.
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All authors Mauro Menichelli, Aishah Bashiri, Marco Bizzarri, Lucio Calcagnile, Mirco Caprai, Domenico Caputo, Anna P. Caricato, Sara M. Carturan, Massimo Cazzanelli, Andrea Cesarini, Marco Cinausero, Federico Cittadini, Tommaso Croci, Sylvain Dunand, Michele Fabi, Giorgia Franchin, Benedetta Gianfelici, Antonella Giuri, Catia Grimani, Hamza Hasnaoui, Giacomo Insero, Maria Ionica, Keida Kanxheri, Nicola Lovecchio, Gianluigi Maggioni, Giuseppe Maruccio, Anna G. Monteduro, Arianna Morozzi, Augusto Nascetti, Stefania Pallotta, Andrea Papi, Daniele Passeri, Maddalena Pedio, Marco Petasecca, Pisana Placidi, Matteo Polo, Marta Ponzecchi, Alberto Quaranta, Gianluca Quarta, Walter Raniero, Silvia Rizzato, Aurora Rizzo, Federico Sabbatini, Rabia Sandhu, Leonello Servoli, Cinzia Talamonti, Alberto Verdini, Mattia Villani, Nicolas Wyrsch

Fluid Dynamics

Vortex formation around islands in random waves

Alex J. Vernon, Junyi Ye, Wenzhe Liu et al. (+2 more)

Wave vortices are fundamental topological features of interference fields, occurring at nodal points where the wave amplitude vanishes. A distinct class of vortices can instead form around it islands or `holes' in two-dimensional wavefields, where the wave intensity remains finite and may even peak at the boundary. In particular, such vortices occur in M2 ocean tides around New Zealand, Madagascar, Iceland, and Svalbard, yet the conditions governing their appearance have remained elusive. Here we develop a statistical theory of vortices around islands in random two-dimensional wavefields, with and without the Coriolis effect, and test it experimentally. We determine the probabilities of vortices with different topological charges as functions of island size and Coriolis parameter. We find that island-bound vortices emerge with unexpectedly high probability, approaching 50% in non-rotating systems and nearly 100% in rotating systems. Moreover, for a broad range of parameters, the presence of a subwavelength island dramatically enhances vortex formation compared with homogeneous random wavefields. Our results explain the formation of tidal vortices around ocean islands of particular sizes (~0.1 of the characteristic wavelength) and establish a general mechanism for generating localized high-intensity vortices around defects in diverse wave systems, from water waves to nanophotonic structures.
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All authors Alex J. Vernon, Junyi Ye, Wenzhe Liu, Lei Shi, Konstantin Y. Bliokh

Instrumentation and Detectors

Operation and performance of ProtoDUNE Dual Phase liquid argon time projection chamber

DUNE Collaboration: S. Abbaslu, F. Abd Alrahman, A. Abed Abud et al. (+1362 more)

ProtoDUNE-DP was the largest ever built Liquid Argon Time Projection Chamber (LArTPC) operating in Dual-Phase (DP) mode, with a liquid target and charge read-out placed in the gas. It had an active volume of $6\times6\times6$\,m$^3$ corresponding to an active mass of 300\,t (total LAr mass of 720\,t), constructed at the CERN Neutrino Platform and took data from 2019 to 2020 with cosmic muons. In ProtoDUNE-DP the electric drift field is oriented in the vertical direction, causing the electrons to drift vertically towards the anode at the top. The ionization charge is then extracted into the gaseous argon above the liquid surface, amplified by Townsend avalanches, and collected by the charge readout planes. The detector experienced significant technical problems affecting the long-term operation of the Charge Readout Planes, formed by the Large Electron Multipliers, but other critical segments demonstrated required performance including the delivery of -300 kV to the TPC cathode, verification of replaceable charge read-out electronics, and operation of the photon detection system. ProtoDUNE-DP experience resulted in improved designs of the Vertical Drift LArTPC.
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All authors DUNE Collaboration: S. Abbaslu, F. Abd Alrahman, A. Abed Abud, R. Acciarri, L. P. Accorsi, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, K. Adhikari, C. Adriano, K. Agudelo-Jaramillo, F. Akbar, F. Alemanno, N. S. Alex, L. Aliaga Soplin, A. Alqaisi, M. Alrashed, A. Alton, R. Alvarez, T. Alves, A. Aman, H. Amar, R. Amarinei, P. Amedo, E. P. M. Amorim, J. Anderson, D. A. Andrade, C. Andreopoulos, M. Andreotti, M. P. Andrews, F. Andrianala, S. Andringa, F. Anjarazafy, S. Ansarifard, D. Antic, A. Antonakis, A. Aranda-Fernandez, T. Araya-Santander, L. Arellano, E. Arrieta Diaz, M. A. Arroyave, M. Artero Pons, J. Asaadi, M. Ascencio, A. Ashkenazi, L. Asquith, E. Atkin, D. Auguste, A. Aurisano, V. Aushev, D. Autiero, D. Ávila Gómez, M. B. Azam, F. Azfar, J. J. Back, Y. Bae, I. Bagaturia, L. Bagby, H. Bagdu, R. Bajou, S. Balasubramanian, A. Balboni, P. Baldi, W. Baldini, J. Baldonedo, B. Baller, B. Bambah, F. Barao, D. Barbu, G. Barenboim, P. Barham Alzás, G. J. Barker, W. Barkhouse, E. Barlas Yucel, G. Barr, W. Barrett, D. Barrow, J. L. Barrow, A. Basharina-Freshville, A. Bashyal, V. Basque, M. Bassani, D. Basu, L. Bathe-Peters, J. G. Batista Sigolo, J.B.R. Battat, F. Battisti, J. Bautista, F. Bay, J. L. L. Bazo Alba, J. F. Beacom, E. Bechetoille, A. Beever, B. Behera, E. Belchior, B. Bell, G. Bell, L. Bellantoni, G. Bellettini, V. Bellini, O. Beltramello, C. Benitez Montiel, D. Benjamin, K. Benslama, F. Bento Neves, J. Berger, S. Berkman, J. Bermudez, J. Bernal, P. Bernardini, A. Bersani, E. Bertholet, E. Bertolini, S. Bertolucci, M. Betancourt, A. Betancur Rodríguez, Y. Bezawada, A. T. Bezerra, A. Bhat, V. Bhatnagar, M. Bhattacharjee, S. Bhattacharjee, M. Bhattacharya, S. Bhuller, B. Bhuyan, S. Biagi, J. Bian, K. Biery, B. Bilki, A. Binau, M. Bishai, A. Blake, A. Blanchet, F. D. Blaszczyk, G. C. Blazey, E. Blucher, A. Bodek, B. Bogart, J. Boissevain, T. Bolton, L. Bomben, M. Bonesini, C. Bonilla-Diaz, A. Booth, F. Boran, C. Borden, R. Borges Merlo, D. Borodulina, N. Bostan, G. Botogoske, B. Bottino, R. Bouet, J. Boza, B. Brahma, D. Brailsford, F. Bramati, A. Branca, A. Brandt, J. Bremer, S. J. Brice, S. Brickner, V. Brio, C. Brizzolari, C. Bromberg, J. Brooke, A. Bross, G. Brunetti, M. B. Brunetti, N. Buchanan, H. Budd, J. Buergi, A. Bundock, D. Burgardt, S. Butchart, G. Caceres V., R. Calabrese, J. Calcutt, L. Calivers, S. Calvez, E. Calvo, A. Caminata, A. F. Camino, W. Campanelli, A. Campani, A. Campos Benitez, N. Canci, J. Capó, I. Caracas, D. Caratelli, D. Carber, G. Carini, M. F. Carneiro, P. Carniti, I. Caro Terrazas, H. Carranza, N. Carrara, L. Carroll, A. Carter, J. Carvalho Roberto, E. Casarejos, D. Casazza, J. F. Castaño Forero, F. A. Castaño, C. Castromonte, E. Catano-Mur, C. Cattadori, F. Cavalier, F. Cavanna, S. Centro, G. Cerati, C. Cerna, A. Cervelli, A. Cervera Villanueva, J. Chakrani, M. Chalifour, A. Chappell, A. Chatterjee, B. Chauhan, C. Chavez Barajas, H. Chen, M. Chen, W. C. Chen, Y. Chen, Z. Chen, D. Cherdack, S. S. Chhibra, C. Chi, F. Chiapponi, R. Chirco, N. Chitirasreemadam, K. Cho, S. Choate, G. Choi, D. Chokheli, P. S. Chong, O. Chow, B. Chowdhury, D. Christian, E. Church, M. F. Cicala, M. Cicerchia, V. Cicero, R. Ciolini, P. Clarke, G. Cline, A. G. Cocco, J. A. B. Coelho, J. Collazo, J. Collot, H. Combs, J. M. Conrad, L. Conti, T. Contreras, M. Convery, K. Conway, S. Copello, P. Cova, C. Cox, L. Cremonesi, J. I. Crespo-Anadón, M. Crisler, E. Cristaldo, J. Crnkovic, G. Crone, R. Cross, T. Cruz, A. Cudd, C. Cuesta, Y. Cui, F. Curciarello, D. Cussans, O. Dalager, W. Dallaway, R. D'Amico, H. da Motta, Z. A. Dar, R. Darby, L. Da Silva Peres, Q. David, G. S. Davies, S. Davini, J. Dawson, R. De Aguiar, K. H. De Barros, P. Debbins, M. P. Decowski, A. de Gouvêa, P. C. De Holanda, P. De Jong, P. Del Amo Sanchez, G. De Lauretis, A. Delbart, M. Delgado, A. Dell'Acqua, G. Delle Monache, N. Delmonte, P. De Lurgio, G. De Matteis, J. R. T. de Mello Neto, A. P. A. De Mendonca, D. M. DeMuth, S. Dennis, C. Densham, P. Denton, G. W. Deptuch, V. De Romeri, J. P. Detje, J. Devine, K. Dhanmeher, R. Dharmapalan, M. Dias, A. Diaz, J. S. Díaz, F. Díaz, F. Di Capua, A. Di Domenico, S. Di Domizio, S. Di Falco, D. Di Ferdinando, L. Di Giulio, P. Ding, L. Di Noto, E. Diociaiuti, G. Di Sciascio, C. Distefano, R. Di Stefano, R. Diurba, M. Diwan, Z. Djurcic, S. Dolan, M. Dolce, M. J. Dolinski, D. Domenici, S. Dominguez, S. Donati, S. Doran, S. Dos Santos Moreira, D. Douglas, T.A. Doyle, F. Drielsma, D. J. Drobner, D. Duchesneau, K. Duffy, K. Dugas, P. Dunne, S. Durando, B. Dutta, D. A. Dwyer, A. S. Dyshkant, S. Dytman, M. Eads, A. Earle, S. Edayath, D. Edmunds, J. Eisch, S. Elias, J. Ellis, W. Emark, P. Englezos, A. Ereditato, D. T. Ergonul, T. Erjavec, C. O. Escobar, G. Eurin, J. J. Evans, E. Ewart, A. C. Ezeribe, K. Fahey, A. Falcone, C. Fang, M. Fani', F. Fanomezana, D. Faragher, C. Farnese, Y. Farzan, J. Felix, Y. Feng, M. Ferreira da Silva, E. Fialova, L. Fields, P. Filip, A. Filkins, F. Filthaut, G. Fiorillo, M. Fiorini, N. F. Fiuza De Barros, S. Fogarty, W. Foreman, B. Fossing, J. Fowler, J. Franc, K. Francis, D. Franco, J. Franklin, J. Freeman, J. Fried, A. Friedland, S. Fuess, I. K. Furic, K. Furman, A. P. Furmanski, R. Gaba, A. Gabrielli, A. M. Gago, F. Galizzi, H. Gallagher, M. Galli, N. Gallice, V. Galymov, E. Gamberini, T. Gamble, R. Gan, R. Gandhi, S. Ganguly, F. Gao, S. Gao, A. Garcia, D. Garcia-Gamez, M. Á. García-Peris, V. Garcia Pol, F. Gardim, S. Gardiner, P. Gauzzi, G. Ge, N. Geffroy, B. Gelli, S. Gent, A. Ghosh, A. Ghosh, T. Giammaria, D. Gibin, I. Gil-Botella, A. Gioiosa, S. Giovannella, A. K. Giri, V. Giusti, D. Gnani, O. Gogota, S. Gollapinni, K. Gollwitzer, R. A. Gomes, L. S. Gomez Fajardo, D. Gonzalez-Diaz, J. Gonzalez-Santome, M. C. Goodman, S. Goswami, C. Gotti, J. Goudeau, C. Grace, E. Gramellini, R. Gran, P. Granger, C. Grant, D. R. Gratieri, P. Green, S. Greenberg, W. C. Griffith, A. Gruber, K. Grzelak, L. Gu, W. Gu, V. Guarino, M. Guarise, R. Guenette, M. Guerzoni, D. Guffanti, A. Guglielmi, F. Y. Guo, A. Gupta, V. Gupta, G. Gurung, D. Gutierrez, P. Guzowski, M. M. Guzzo, S. Gwon, A. Habig, R. Hafeji, L. Hagaman, A. Hahn, J. Hakenmüller, A. Hambardzumyan, T. Hamernik, P. Hamilton, J. Hancock, M. Handley, F. Happacher, B. Harris, D. A. Harris, L. Harris, A. L. Hart, J. Hartnell, T. Hartnett, T. Hasegawa, C. M. Hasnip, K. Hassinin, R. Hatcher, S. Hawkins, J. Hays, M. He, A. Heavey, K. M. Heeger, A. Heindel, J. Heise, K. Heller, P. Hellmuth, L. Henderson, A. Hergenhan, J. Hernández, M. A. Hernandez Morquecho, K. Herner, V. Hewes, A. Higuera, K. Hildebrandt, A. Himmel, E. Hinkle, L.R. Hirsch, J. Ho, J. Hoefken Zink, A. Holin, C. Hong, S. Horiuchi, G. A. Horton-Smith, R. Hosokawa, T. Houdy, B. Howard, I. Hristova, M. S. Hronek, Y. Hua, J. Huang, R.G. Huang, X. Huang, Z. Hulcher, A. Hussain, G. Iles, N. Ilic, A. M. Iliescu, R. Illingworth, F. Imamoglu, G. Ingratta, A. Ioannisian, M. Ismerio Oliveira, C.M. Jackson, A. Jacobi, V. Jain, C. James, E. James, W. Jang, B. Jargowsky, D. Jena, I. Jentz, C. Jiang, J. Jiang, A. Jipa, J. H. Jo, F. R. Joaquim, A. M. Johnson, W. Johnson, C. Jollet, M. Joshi, N. Jovancevic, M. Judah, C. K. Jung, K. Y. Jung, T. Junk, Y. Jwa, M. Kabirnezhad, A. C. Kaboth, I. Kadenko, O. Kalikulov, D. Kalra, M. Kandemir, S. Kar, C. Karagianni, G. Karagiorgi, G. Karaman, A. Karcher, Y. Karyotakis, S. P. Kasetti, L. Kashur, A. Kauther, N. Kazaryan, L. Ke, E. Kearns, P.T. Keener, A. Kelly, K.J. Kelly, R. Keloth, O. Kemularia, J. Kerby, Y. Kermaidic, W. Ketchum, S. H. Kettell, N. Khan, A. Khvedelidze, D. Kim, J. Kim, M. J. Kim, S. Kim, B. King, M. King, M. Kirby, A. Kish, J. Klein, J. Kleykamp, T. Kobilarcik, L. Koch, K. Koehler, L. W. Koerner, D. H. Koh, K. Kong, M. Kordosky, V. A. Kostelecký, I. Kotler, M. Kramer, F. Krennrich, T. Kroupova, S. Kubota, M. Kubu, V. A. Kudryavtsev, G. Kufatty, A. Kumar, J. Kumar, M. Kumar, P. Kumar, S. Kumaran, J. Kunzmann, P. Kunzé, V. Kus, T. Kutter, J. Kvasnicka, T. Labree, M. Lachat, T. Lackey, I. Lalău, A. Lambert, B. J. Land, C. E. Lane, N. Lane, K. Lang, M. Langstaff, F. Lanni, S. Lanzi, J. Larkin, P. Lasorak, D. Last, G. Laurenti, E. Lavaut, W. Lavrijsen, H. Lay, I. Lazanu, R. LaZur, M. Lazzaroni, S. Leardini, J. Learned, G. Lehmann Miotto, R. Lehnert, M. Leitner, H. Lemoine, D. Leon Silverio, L. M. Lepin, J.D. Lewis, J.-Y Li, S. W. Li, Y. Li, R. C. R. Lima, R. Lima, C. S. Lin, D. Lindebaum, S. Linden, A. Lister, B. R. Littlejohn, J. Liu, Y. Liu, M. Lkhagvadorj, S. Lockwitz, I. Lomidze, J.Lopez, I. López de Rego, N. López-March, A. Lopez Moreno, J. M. LoSecco, A. Lozano Sanchez, X.-G. Lu, K.B. Luk, X. Luo, G. Lupi, E. Luppi, A. A. Machado, P. Machado, C. T. Macias, J. R. Macier, L. F. B. Magalhães Rodrigues, S. Magill, C. Magueur, K. Mahn, A. Maio, N. Majeed, K. Majumdar, A. Malige, S. Mameli, M. Man, R. C. Mandujano, J. Maneira, S. Manly, K. Manolopoulos, M. Manrique Plata, S. Manthey Corchado, L. Manzanillas-Velez, E. Mao, M. Marchan, A. Marchionni, D. Marfatia, C. Mariani, J. Maricic, R. Marie, F. Marinho, A. D. Marino, T. Markiewicz, F. Das Chagas Marques, M. Marshak, C. M. Marshall, J. Marshall, J. Martin, M. Martin, L. Martina, J. Martín-Albo, D.A. Martinez Caicedo, M. Martinez-Casales, F. Martínez López, S. Martynenko, V. Mascagna, A. Mastbaum, M. Masud, F. Matichard, J. Matthews, C. Mauger, N. Mauri, K. Mavrokoridis, I. Mawby, T. McAskill, N. McConkey, B. McConnell, K. S. McFarland, C. McGivern, C. McGrew, A. McNab, C. McNulty, J. Mead, L. Meazza, V. C. N. Meddage, A. Medhi, M. Mehmood, B. Mehta, P. Mehta, F. Mei, P. Melas, L. Mellet, T. C. D. Melo, O. Mena, D. P. Méndez, A. Menegolli, G. Meng, A. Mengarelli, A. C. E. A. Mercuri, A. Meregaglia, G. Merino, M. D. Messier, S. Metallo, W. Metcalf, M. Mewes, H. Meyer, T. Miao, J. Micallef, A. Miccoli, G. Michna, R. Milincic, F. Miller, G. Miller, W. Miller, A. Minotti, L. Miralles Verge, C. Mironov, S. Miscetti, P. Mishra, S. R. Mishra, D. Mladenov, I. Mocioiu, A. Mogan, P. S. Mohan, R. Mohanta, T. A. Mohayai, N. Mokhov, J. Molina, L. Molina Bueno, E. Montagna, A. Montanari, C. Montanari, D. Montanari, D. Montanino, L. M. Montaño Zetina, M. Mooney, A. F. Moor, M. Moore, Z. Moore, B. Moreira, D. Moreno, G. Moreno-Granados, O. Moreno-Palacios, L. Morescalchi, A. Morita, E. Motuk, C. A. Moura, W. Mu, L. Mualem, J. Mueller, M. Muether, A. Muir, Y. Mukhamejanov, A. Mukhamejanova, E. Muldoon, M. Mulhearn, D. Munford, L. J. Munteanu, H. Muramatsu, J. Muraz, M. Murphy, T. Murphy, A. Mytilinaki, J. Nachtman, Y. Nagai, S. Nagu, H. Nam, D. Naples, S. Narita, J. Nava, D. Navas-Nicolás, A. Navrer-Agasson, N. Nayak, M. Nebot-Guinot, A. Nehm, J. K. Nelson, O. Neogi, J. Nesbit, M. Nessi, D. Newbold, M. Newcomer, D. Newmark, L. Nguyen, R. Nichol, F. J. Nicolas-Arnaldos, A. Nielsen, A. Nikolica, J. Nikolov, E. Niner, X. Ning, K. Nishimura, A. Norman, N. Noroozi, A. Norrick, F. Noto, P. Novella, A. Nowak, J. A. Nowak, M. Oberling, J. P. Ochoa-Ricoux, S. Oh, S.B. Oh, L. Olaya-Quemba, A. Olivier, T. Olson, Y. Onel, A. Oranday, G. P. Orebi Gann, A. I. R. Orimogunje, M. Osbiston, J. E. Ossa Sanchez, L. O'Sullivan, L. Otiniano Ormachea, L. Pagani, O. Palamara, S. Palestini, J. M. Paley, M. Pallavicini, C. Palomares, B. Pan, S. Pan, M. Panareo, P. Panda, V. Pandey, W. Panduro Vazquez, E. Pantic, V. Paolone, A. Papadopoulou, R. Papaleo, D. Papoulias, S. Paramesvaran, J. Park, J. Park, Y. Park, S. Parke, S. Parsa, M. Parvu, D. Pasciuto, S. Pascoli, L. Pasqualini, G. Patel, J. L. Paton, C. Patrick, L. Patrizii, R. B. Patterson, T. Patzak, A. Paudel, L. Paulucci, Z. Pavlovic, G. Pawloski, D. Payne, A. Peake, V. Pec, E. Pedreschi, L. Pelegrina-Gutiérrez, W. Pellico, E. Pennacchio, A. Penzo, O. L. G. Peres, Y. F. Perez Gonzalez, L. Pérez-Molina, C. Pernas, J. Perry, D. Pershey, G. Pessina, G. Petrillo, C. Petta, R. Petti, M. Pfaff, V. Pia, G. M. Piacentino, L. Pickering, G. Piemonti, L. Pierini, F. Pietropaolo, M. Pimenta Sampaio, V.L.Pimentel, G. Pinaroli, S. Pincha, J. Pinchault, K. Pitts, P. Plesniak, K. Pletcher, K. Plows, C. Pollack, F. Polleri, T. Pollmann, F. Pompa, X. Pons, N. Poonthottathil, F. Poppi, J. Porter, L. G. Porto Paixao, M. Pozzato, R. Pradhan, L. Prais, T. Prakash, M. Prest, D. Pugnere, D. Pullia, X. Qian, J. Quelin-Lechevranton, J. L. Raaf, V. Radeka, J. Rademacker, F. Raffaelli, A. Rafique, U. Rahaman, A. Rahe, S. Rajagopalan, M. Rajaoalisoa, I. Rakhno, L. Rakotondravohitra, M. A. Ralaikoto, L. Ralte, L. Ralte, M. A. Ramirez Delgado, B. Ramson, A. Rappoldi, G. Raselli, T. Rath, P. Ratoff, R. Raut, R. Ray, H. Razafinime, R. F. Razakamiandra, E. M. Rea, J. S. Real, B. Rebel, R. Rechenmacher, M. Reggiani-Guzzo, J. Reichenbacher, S. D. Reitzner, E. Renner, S. Repetto, S. Rescia, F. Resnati, J. V. Restrepo Laverde, C. Reynolds, S. Riboldi, C. Riccio, G. Riccobene, J. S. Ricol, M. Rigan, A. Rikalo, A. Ritchie-Yates, D. Rivera, A. Rivetti, A. Robert, E. Robles, A. Roche, M. Roda, D. Rodas Rodríguez, M. J. O. Rodrigues, J. Rodriguez Rondon, S. Rosauro-Alcaraz, P. Rosier, D. Ross, M. Rossella, M. Ross-Lonergan, N. Roy, P. Roy, C. Royon, C. Rubbia, A. Ruggeri, G. Ruiz Ferreira, K. Rushiya, B. Russell, E. Sabater Andres, S. Sacerdoti, N. Saduyev, D. Sagar, S. Saha, S. K. Sahoo, N. Sahu, S. Sakhiyev, P. Sala, N. Sallin, G. Salmoria, S. Samanta, M. C. Sanchez, A. Sánchez-Castillo, P. Sanchez-Lucas, D. A. Sanders, S. Sanfilippo, G. Santoni, D. Santoro, N. Saoulidou, P. Sapienza, I. Sarcevic, I. Sarra, C. Sauer, L. Sauer, G. Savage, V. Savinov, A. Scanu, A. Scaramelli, T. Schefke, H. Schellman, S. Schifano, P. Schlabach, D.W. Schmitz, A. W. Schneider, K. Scholberg, A. Schroeder, A. Schukraft, B. Schuld, S. Schwartz, A. Segade, H. Segal, E. Segreto, A. Selyunin, D. Senadheera, C. R. Senise, J. Sensenig, S.H. Seo, D. Seppela, M. H. Shaevitz, P. Shanahan, P. Sharma, R. Kumar, S. Sharma Poudel, K. Shaw, T. Shaw, J. Shen, C. Shepherd-Themistocleous, J. Shi, W. Shi, S. Shin, S. Shivakoti, A. Shmakov, I. Shoemaker, D. Shooltz, R. Shrock, M. Siden, J. Silber, L. Simard, J. Sinclair, G. Sinev, Jaydip Singh, J. Singh, L. Singh, P. Singh, V. Singh, S. Singh Chauhan, R. Sipos, C. Sironneau, G. Sirri, K. Siyeon, K. Skarpaas, J. Smedley, J. Smith, R. S. Smith-Jones, J. Smolik, M. Smy, M. Snape, E. L. Snider, P. Snopok, M. Soares Nunes, H. Sobel, M. Soderberg, H. Sogarwal, C. J. Solano Salinas, S. Söldner-Rembold, N. Solomey, V. Solovov, W. E. Sondheim, T. Sonius, M. Sorbara, M. Sorel, J. Soto-Oton, A. Sousa, K. Soustruznik, D. Souza Correia, F. Spinella, J. Spitz, N. J. C. Spooner, D. Stalder, M. Stancari, L. Stanco, J. Steenis, R. Stein, H. M. Steiner, A. F. Steklain Lisbôa, J. Stewart, B. Stillwell, J. Stock, T. Stokes, T. Strauss, L. Strigari, A. Stuart, W. Su, A. Surdo, L. Suter, A. Sutton, R. Svoboda, S. K. Swain, C. Sweeney, B. Szczerbinska, A. M. Szelc, A. Sztuc, A. Taffara, N. Talukdar, J. Tamara, H. A. Tanaka, S. Tang, N. Taniuchi, A. M. Tapia Casanova, A. Tapper, S. Tariq, E. Tatar, R. Tayloe, A. M. Teklu, K. Tellez Giron Flores, J. Tena Vidal, P. Tennessen, M. Tenti, K. Terao, F. Terranova, S. Teruel, G. Testera, A. Thea, S. Thomas, A. Thompson, C. Thorpe, M. Timalsina, S. C. Timm, E. Tiras, V. Tishchenko, S. Tiwari, N. Todorović, L. Tomassetti, A. Tonazzo, D. Torbunov, D. Torres Muñoz, M. Torti, M. Tortola, Y. Torun, N. Tosi, D. Totani, M. Toups, C. Touramanis, V. Trabattoni, D. Tran, P. Trevarrow, J. Trevor, E. Triller, S. Trilov, D. Trotta, W. H. Trzaska, Y. Tsai, Y.-T. Tsai, Z. Tsamalaidze, K. V. Tsang, N. Tsverava, S. Z. Tu, S. Tufanli, C. Tunnell, S. Turnberg, J. Turner, M. Tuzi, M. Tzanov, J. Ureña González, J. Urheim, T. Usher, H. Utaegbulam, S. Uzunyan, M. R. Vagins, P. Vahle, G. A. Valdiviesso, E. Valencia, R. Valentim da Costa Lima, Z. Vallari, E. Vallazza, J. W. F. Valle, R. Van Berg, D. V. Forero, P. Van Gemmeren, A. Vannozzi, M. Van Nuland-Troost, F. Varanini, N. Vaughan, K. Vaziri, A. Vázquez-Ramos, J. Vega, J. Vences, S. Ventura, A. Verdugo, M. Verzocchi, J. Vesic, K. Vetter, M. Vicenzi, H. Vieira de Souza, C. Vignoli, C. Vilela, E. Villa, S. Viola, B. Viren, G. V. Stenico, R. Vizarreta, A. P. Vizcaya Hernandez, S. Vlachos, G. Vorobyev, Q. Vuong, A. V. Waldron, L. Walker, H. Wallace, M. Wallach, J. Walsh, T. Walton, L. Wan, B. Wang, J. Wang, L. Wang, M.H.L.S. Wang, X. Wang, Y. Wang, Y. Wang, D. Warner, L. Warsame, M.O. Wascko, D. Waters, A. Watson, K. Wawrowska, A. Weber, C. M. Weber, M. Weber, H. Wei, A. Weinstein, S. Westerdale, M. Wetstein, Q. Weyrich, K. Whalen, A.J. White, L. H. Whitehead, D. Whittington, F. Wieler, J. Wilhelmi, M. J. Wilking, A. Wilkinson, C. Wilkinson, R. J. Wilson, P. Winter, J. Wolcott, J. Wolfs, T. Wongjirad, A. Wood, K. Wood, E. Worcester, M. Worcester, K. Wresilo, M. Wright, M. Wrobel, S. Wu, Z. Wu, J. Wyenberg, B. M. Wynne, Y. Xiao, Z. Xie, D. Xing, B. Yaeggy, A. Yahaya, N. Yahlali, E. Yandel, G. Yang, J. Yang, T. Yang, A. Yankelevich, L. Yates, U. Yevarouskaya, K. Yonehara, T. Young, B. Yu, H. Yu, J. Yu, K. Yu, X. Yu, W. Yuan, R. Zaki, J. Zalesak, L. Zambelli, B. Zamorano, A. Zani, L. Zazueta, G. P. Zeller, J. Zennamo, J. Zettlemoyer, K. Zeug, C. Zhang, S. Zhang, Y. Zhang, L. Zhao, M. Zhao, K. Zhu, E. D. Zimmerman, S. Zucchelli, A. Zummo, V. Zutshi, R. Zwaska

Optics

Sub-microsecond conformational dynamics in an optical nanocavity

Heehun Sung, Sam C Scholten, Pavlina Sasheva et al. (+2 more)

Microsecond conformational changes underlie many protein functions, but ensemble averaging has been needed to observe them without labels. Single-shot measurements on individual proteins have had insufficient speed, while protein Brownian-motion has obscured signals. Here, we report a fibre-integrated silicon-photonic sensor that overcomes these barriers, resolving protein dynamics at sub-microsecond speeds in continuous single-shot measurements that can extend over minutes. This is achieved by combining far-sub-wavelength optical field confinement with high optical field uniformity that suppresses protein Brownian-motion by a factor of sixty. In single-shot measurements on ferritin molecules, we observe tens of thousands of transitions consistent with conformational fluctuations of the ferritin shell, resolving them over timescales as short as 400 ns. The ability to continuously monitor transitions over long times reveals switching kinetics, memory effects and molecular heterogeneity hidden in ensemble averages. This opens a new path to improved mechanistic understanding of protein function.
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All authors Heehun Sung, Sam C Scholten, Pavlina Sasheva, Igor Marinkovic, Warwick P Bowen

Plasma Physics

Relativistic Scaling and Magnetization-Current Feedback in Stern Gerlach-Modified Pair-Plasma Reconnection: SpinPIC2D Validation and Nonlinear Regimes

K. Nykyri

We investigate the relativistic scaling and electromagnetic feedback of Stern–Gerlach (SG) force driven spin transport in pair-plasma reconnection with SpinPIC2D. The model advances relativistic proper momentum and magnetic BMT spin precession, applies the SG force, deposits spin magnetization, and includes $\mathbf J_M=\nabla\times\mathbf M$ in Ampere's law. In a weak-seed scan at fixed $\gamma_{\rm tr}=2$, the normalized global magnetic flux-growth remains near the classical control-run for $\Xi\le0.1$, is $0.016$ at $\Xi=0.4$, and reaches approximately $0.12$ and $0.25$ at $\Xi=0.7$ and 1, respectively over $3\le t/\tau_{\rm sp}\le7$. Because $\partial/\partial y=0$ in the 2.5-D geometry, the direct $y$-directed SG term vanishes and the enhancement is indirect: sheet-normal SG sorting restructures branch-resolved electron and positron velocity distributions which results in changes in pressure moments and generates a layered magnetization current. Along a fixed-$\chi_{\rm sim}$ family, increasing $\gamma_{\rm tr}$ reduces $\Xi$ and suppresses branch sorting, whereas the matched-control flux-growth enhancement remains positive for $\gamma_{\rm tr}=2,3,5$. Retuning $\chi_{\rm sim}$ to hold $\Xi=1$ does not preserve nonlinear similarity: both the coupling and $J_{M,y}$ increase with $\gamma_{\rm tr}$, and the $\gamma_{\rm tr}=5$ case develops a multi-X-line state. Thus $\Xi$ orders the onset of SG-modified reconnection, while the nonlinear response also depends on the absolute spin coupling and magnetization-current amplitude.
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Computational Physics

Atomic Design Transformer: Scaffold-Conditioned 3D Molecule Generation with xTB-Verified Reinforcement Learning

Takao Kotani

We present an autoregressive 3D-molecule generator with SE(3)-invariant tokenization, the Atomic Design Transformer (ADT). ADT places atoms one at a time, autoregressively. SE(3) invariance is achieved by tokenization: each new atom's position is encoded in the local coordinate frame of a previously placed atom. The backbone is a plain causal transformer. The token stream fully specifies a 3D structure together with its chemical-bond graph G, without any bond-order assignment. The model emits heavy-atom skeletons; hydrogens are added by separate learned models before the xTB relaxation. To score generated molecules we introduce the xTB topology-preservation rate (XTP): the fraction of molecules for which an xTB GFN2 relaxation preserves G specified by the token stream. For XTP-accepted molecules we also report the relaxation energy and the root mean square of the atomic displacement (RMSD). We evaluate two ADT models. The first is ADT pretrained on the GEOM-Drugs $\le\!30$-heavy-atom dataset; we benchmark scaffold-conditioned 3D generation across seven drug-like scaffolds from the model. It reaches an XTP of ${\sim}55\%$ and a valid-molecule yield $N^{\mathrm{gen}}/N$ of ${\sim}53\%$, where $N^{\mathrm{gen}}/N$ is the fraction of samples that are distinct, topology-preserving, and RDKit-readable. The second model continues from the first by reinforcement learning against the verifiable xTB reward (RLVR), using no external molecules. RLVR raises XTP to ${\sim}98\%$ and $N^{\mathrm{gen}}/N$ to ${\sim}95\%$, while approximately preserving the GEOM-Drugs size and composition distributions. Finally, we present an Inverse-Kinematics Transformer that recovers XTP for large molecules, where discretization error accumulates. ADT thus enables direct 3D generation.
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2607.15918 · 17 Jul · 8 pages. Code and data: github.com/tkotani/ADT (v2.1), doi:10.5281/zenodo.20635985; one instruction to an AI coding agent regenerates the benzene row of Table 2 from the released checkpoint (~1 h on one GPU). v2: new title; RLVR model released as rlvr_E240direct.pt; scaffold frame caches corrected; all generation numbers re-tabulated with one public script; text revised

Abstract PDF $TRFM ×4$TOKN ×2$TOPO ×2$BNCH ×1 +1

Instrumentation and Detectors

Precision positioning in free-space optical communication systems via PID control tuned by RL

K. Prikhodko, S. Kuznetsov, S. Vorobey et al. (+3 more)

Accurate positioning of optical components is essential for maintaining beam alignment in free-space optical (FSO) communication systems. This work investigates reinforcement-learning-assisted tuning of cascaded position and velocity PID controllers for an optical deflector that moves the end of an optical fiber in the focal plane of an optical system. A Deep Deterministic Policy Gradient (DDPG) agent adjusts six PID coefficients through interaction with a physical experimental stand. The stand supports target-coordinate updates of up to $12$ kHz, while the agent and the controlled device are located approximately $200$ km apart and exchange data over UDP. After $5000$ training sessions, two fixed coefficient sets are selected and compared with a manually tuned baseline. For a pseudo-random target trajectory, the best RL-tuned set reduces the range of the radial positioning error from $119$ to $82$, corresponding to a $31\%$ reduction, and decreases its standard deviation from $15$ to $12$. For a constant zero target, the RL-tuned sets do not improve the radial error range. The results demonstrate the potential of DDPG for experimental PID tuning in dynamic positioning tasks and indicate the need for multi-regime optimization to achieve consistent performance under different operating conditions.
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All authors K. Prikhodko, S. Kuznetsov, S. Vorobey, A. Katanskiy, V. Balakirev, A. Reutov

Instrumentation and Detectors

Nuclotron internal target polarimeter for the measurements of the deuteron and proton beam polarization

I.S.Volkov, V.P.Ladygin, A.V.Averyanov et al. (+16 more)

Studies of spin-dependent effects at the Nuclotron/NICA accelerator complex at JINR require precise measurements of the deuteron and proton beam polarization. The vector polarization of the deuteron beam was measured at the energies of 200, 500, 550, and 650 MeV/nucleon by a detection system of scintillation counters placed at the Nuclotron internal target. Considering the deuteron beam as a beam of weakly bound protons and neutrons, the asymmetries of scattering of protons from deuterons on polyethylene and carbon targets were determined. The polarization of the polarized proton beam accelerated for the first time at the Nuclotron up to 500 MeV was also measured.
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All authors I.S.Volkov, V.P.Ladygin, A.V.Averyanov, E.V.Chernykh, D.Enache, Yu.V.Gurchin, A.Yu.Isupov, M.Janek, J.-T.Karachuk, D.O.Krivenkov, P.K.Kurilkin, A.N.Livanov, S.M.Piyadin, S.G.Reznikov, Ya.T.Skhomenko, A.A.Terekhin, A.V.Tishevsky, T.Uesaka, I.E.Vnukov

Plasma Physics

Surrogate modeling of drift-reduced Braginskii turbulence with resistivity-conditioned Koopman neural operators

Ameir Shaa, Kyungtak Lim, Long Shan Chan et al. (+1 more)

Machine-learning-driven surrogate operators are developed for three-dimensional, nonlinear, flux-driven simulations of boundary plasma turbulence based on the two-fluid drift-reduced Braginskii model. Resistivity-conditioned Koopman neural operators (KNOs) are trained on Global Braginskii Solver (GBS) simulations, spanning low- to high-resistivity regimes. Separate fieldwise models are constructed for plasma density, electron temperature, electric potential, and vorticity. Evaluation at a held-out resistivity shows that the surrogates reproduce key short-horizon statistical features, including strong one-step agreement, spectral trends, and reduced pressure-gradient diagnostics. Field-dependent limitations remain, with vorticity showing the largest discrepancies and autoregressive rollout progressively departing from the reference simulation. The results demonstrate that resistivity-conditioned fieldwise neural operators provide useful fast emulators for selected boundary-plasma turbulence diagnostics, while stable long-horizon dynamical closure remains unresolved.
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All authors Ameir Shaa, Kyungtak Lim, Long Shan Chan, Claude Guet

Optics

Reconfigurable Nonlocal Light-Emitting Metalens Nanolasers via Bound States in the Continuum

Omar A. M. Abdelraouf

The development of on-chip, reconfigurable coherent light sources operating in the visible spectrum is critical for next-generation optical computing and high-speed data processing. Here, we demonstrate an all-optically tunable nanolaser based on a hybrid dielectric metasurface. The platform integrates a Rhodamine B (Rd B) dye gain medium with a Niobium Pentoxide (Nb2O5) metasurface supporting a high-Q Bound State in the Continuum (BIC) resonance. Active, non-volatile tuning is achieved by incorporating the low-loss phase change material (PCM) Antimony Trisulfide (Sb2S3). We demonstrate room-temperature lasing at 616 nm with Q-factor > 2050. A continuous-wave (CW) laser is utilized for the crystallization of the PCM, tuning the lasing emission to crystalline at 621 nm with Q-factor > 1454, while a near-infrared (NIR) ps-laser triggers its re-amorphization. This robust, thermally protected optical-only control scheme, combined with a phase-gradient metasurface design, realizes a coherent, nonlocal light-emitting metalens for simultaneous lasing wavelength tuning and wavefront control. This work provides a foundational demonstration of an all-optical tunable metalens-based nanolaser for applications in high-speed optical communication, neuromorphic photonics, dynamic holographic displays, and reconfigurable quantum light sources.
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Optics

Conjugate phase-noise cancellation enables submicrometre dual-comb ranging with free-running megahertz-linewidth lasers

Yue You, Zaifan Wu, Yi Zou et al. (+9 more)

Frequency-domain dual-comb ranging combines rapid acquisition with interferometric sensitivity, but high-performance implementations often rely on mutually coherent or actively stabilised comb sources. Free-running sources can reduce this hardware burden, but their phase noise and drift of the optical frequency offset can blur radio-frequency (RF) comb teeth and weaken probe-reference phase correlation. Previous phase-slope implementations have therefore relied on sufficiently resolved RF teeth, within-coherence-length probe-reference paths or explicit digital tracking of these fluctuations. Here we demonstrate a low-cost frequency-domain dual-comb ranging architecture that combines independent free-running distributed-feedback (DFB) lasers with conjugate phase-noise cancellation (CPNC). By forming a self-conjugate signal before the phases of individual RF-comb teeth are extracted, CPNC cancels the common laser phase factor and drifting optical-frequency-offset term while retaining the distance-dependent phase slope. Using electro-optic combs seeded by DFB lasers with linewidths of 12 MHz and 9 MHz, we achieve an Allan deviation of $219~\mathrm{nm}$ at $246~\mu\mathrm{s}$ and reduce the single-frame distance standard deviation from $558~\mu\mathrm{m}$ to $9.31~\mu\mathrm{m}$ with CPNC. Across the tested megahertz-linewidth configurations, CPNC delivered minimum Allan deviations below $250~\mathrm{nm}$. These results show that CPNC enables submicrometre ranging in a low-cost frequency-domain dual-comb architecture with reduced source-stabilisation and phase-management complexity.
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All authors Yue You, Zaifan Wu, Yi Zou, Xiang Cai, Yixiao Zhu, Chenbo Zhang, Dan Lu, Siming Chen, Shujie Pan, Xian Zhou, Xiaopeng Xie, Fan Zhang

Fluid Dynamics

Statistical State Dynamics Eigenmodes and Equilibria support Couette Turbulence

Brian F. Farrell and Petros J. Ioannou

Wide-channel Couette (WCC) turbulence consists primarily of quasi-steady roll-streak structures (RSS) maintained by a self-sustaining process (SSP), yet the Navier-Stokes equations in velocity variables admit no linear RSS instability or stable equilibrium, leaving the WCC turbulent state's analytic basis obscure. We show that, in the statistical state dynamics (SSD) of a second-order closure of the Navier-Stokes equations, Couette turbulence arises from a modal RSS instability and equilibrates as a stable fixed point at spanwise wavenumber 3. This fixed point comprises a streamwise-mean flow and a pair of counterpropagating neutral eigenmodes, regularized by roll advection rather than viscosity. This stable equilibrium identifies both a canonical turbulence solution and its self-sustaining process (SSP), and characterizes their analytic structure. WCC turbulence arises as a spanwise tiling by this stable fixed-point RSS unit cell. Predictions of this SSD theory are corroborated by comparison with direct numerical simulation.
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Medical Physics

Joint-decoupled iterative CBCT reconstruction with hybrid scatter estimation and voxel-adaptive beam hardening correction

Jianing Sun, Jean Michel Létang, Qixiang Sun et al. (+3 more)

Cone-beam computed tomography (CBCT) is fundamentally challenged by scatter and beam hardening artifacts, which originate from X-ray scattering and the polychromatic nature of the X-ray spectrum, respectively. These two types of artifacts are intricately coupled in reconstructed images and manifest with similar streaking and cupping features, severely compromising high-precision CBCT imaging. This paper proposes a physics-driven iterative framework rooted in the polychromatic Polyquant attenuation model, which decouples these artifacts by establishing an optimization loop between scatter estimation and relative electron density (RED) reconstruction. We develop a hybrid strategy for scatter estimation, in which the first-order scattering component is analytically derived based on a polychromatic physical model to preserve high-frequency structural information, whereas the smoother multiple scattering component is efficiently estimated via an object-adaptive convolution module. Subsequently, for beam-hardening correction, we introduce a voxel-adaptive update mechanism that solves linearized, scatter-corrected polychromatic equations to derive optimal weights, enabling direct RED refinement without manual parameter tuning. The proposed method was validated through comprehensive studies on biomedical phantoms, utilizing both Monte Carlo simulations and physical experiments. Representative results demonstrate that the proposed method outperforms state-of-the-art techniques, with the mean relative error decreased from 11.96% to 1.27% for the anthropomorphic head phantom and from 12.55% to 5.46% for the physical Yin-Yang phantom.
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All authors Jianing Sun, Jean Michel Létang, Qixiang Sun, Guangyin Li, Ligen Shi, Xing Zhao

Optics

Experimental demonstration of Flying-Focus enhanced Thomson scattering

E. Gerstmayr, C. Mariani, R. Fitzgarrald et al. (+23 more)

We report the experimental demonstration of a spatiotemporally engineered "Flying-Focus" laser pulse for enhanced x-ray generation in relativistic Thomson scattering. A combination of longitudinal chromatic aberration, angular dispersion, and group delay dispersion was applied to an ultrashort relativistically intense laser pulse to control the motion of its focal point. Precise tuning of the group delay dispersion was used to match the velocity of the focus to the trajectory of a counterpropagating electron bunch, produced by a laser wakefield accelerator. This prolonged the Thomson scattering interaction while reducing nonlinear effects, leading to an enhanced x-ray yield. The approach has the potential to increase the spectral density and brightness of the x-ray beam by orders of magnitude compared to equivalent focusing without spatiotemporal control. This experiment establishes a new technique for structured-light control at high intensity, demonstrating the realization of dynamic intensity structures that enhance light-matter interactions and for the generation of ultra-bright radiation sources.
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All authors E. Gerstmayr, C. Mariani, R. Fitzgarrald, M. VanDusen-Gross, C. Berger, Q. Chen, A. Di Piazza, M.S. Formanek, D.H. Froula, C.G.R. Geddes, A.J. Gonsalves, B. Greenwood, R. Jacob, A. Lu, A. McIlvenny, K. Nakamura, L. Obst-Huebl, J.P. Palastro, A. Picksley, K. Poder, D. Ramsey, H.G. Rinderknecht, G. Sarri, A.G.R Thomas, J. van Tilborg, M.J.V. Streeter

Optics

Triple-Resonance Spectroscopy Using a Cavity-Enhanced Frequency Comb Probe

Qinxue Nie, Vinicius Silva de Oliveira, Adrian Hjältén et al. (+3 more)

Accurate experimentally verified models of molecular hot-band transitions are essential for interpreting high-temperature spectra in environments ranging from exoplanetary atmospheres to combustion systems. However, line-resolved measurements of infrared hot-band transitions reaching highly excited vibrational states above 10000 cm$^{-1}$ are missing because these transitions are too weak to observe at room temperature and become spectrally congested at elevated temperatures. Here, we introduce a nonlinear spectroscopic approach that enables simultaneous measurement of individual infrared hot-band transitions between four vibrational bands up to 12000 cm$^{-1}$ over a broad spectral range with sub-Doppler resolution and sub-MHz frequency accuracy (10$^{-10}$ relative line position accuracy). The methods is based on an all-optical triple-resonance (AOTR) scheme that combines stepwise mid-infrared pumping using an optical-frequency-comb-stabilized, double-seeded continuous-wave optical parametric oscillator with broadband highly sensitive near-infrared probing using a cavity-enhanced optical frequency comb. As a proof of principle, we measure transitions between high polyads (P) of methane - groups of strongly interacting, near-degenerate vibrational energy states arising from couplings between the C-H stretching and bending modes. In a single probe spectrum, we simultaneously resolve sub-Doppler P4$\leftarrow$P0, P6$\leftarrow$P2 and P8$\leftarrow$P4 transitions, reaching the poorly understood polyad P8 near 12000 cm$^{-1}$ and providing the first set of 41 experimentally observed lines in the P8$\leftarrow$P4 spectral region.Comb-based AOTR spectroscopy opens a new route for broadband exploration of highly excited molecular states, delivering extensive high-accuracy spectroscopic data needed to refine molecular models and improve predictions of high-temperature spectra.
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All authors Qinxue Nie, Vinicius Silva de Oliveira, Adrian Hjältén, Isak Silander, Kevin K. Lehmann, Aleksandra Foltynowicz

Accelerator Physics

Alignment and Timing Jitter in Flying-Focus Inverse Compton Scattering

S.G. Rykovanov, I. Dubinkin, M.P. Malakhov et al. (+3 more)

Flying-focus laser pulses can extend the effective interaction length in inverse Compton sources by controlling the trajectory of the focal intensity. Their practical advantage, however, depends on tolerance to shot-to-shot electron–laser alignment and synchronization errors. We develop a semi-analytical model for the shot-averaged total photon yield in head-on inverse Compton scattering of an axisymmetric Gaussian electron bunch with a flying-focus laser pulse. The model includes finite electron-beam emittance, laser diffraction, transverse laser-centroid jitter, longitudinal focus-position jitter, and laser arrival-time jitter at the nominal interaction point. The ensemble averaging over these independent Gaussian errors and the integration over the longitudinal electron and laser coordinates are performed analytically, reducing the overlap problem to a single positive numerical quadrature. This formulation enables rapid evaluation of jitter-robust operating points and provides a compact tool for defining alignment and synchronization tolerances in flying-focus inverse Compton sources.
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All authors S.G. Rykovanov, I. Dubinkin, M.P. Malakhov, A.M. Fedotov, A.S. Samsonov, I.Yu. Kostyukov

Optics

Electromagnetically induced transparency lasing in distributed resonant feedback system

Yaoyao Liang, Xinyue Wang, Hongyi Tian et al. (+3 more)

We demonstrate a loss-enabled mechanism that can realize single electromagnetically induced transparency (EIT) analogue in periodic waveguide-resonator structures. Unlike previously reported passband-based EIT analogues, which arise from compressed passbands in the intrinsic-loss-free limit, the proposed mechanism exploits resonator intrinsic loss to generate an isolated transparency mode within the original bandgap. The resulting EIT state remains immune to finite-size mode discretization, enabling robust single-frequency lasing through distributed resonant feedback while requiring a threshold modal gain lower than that of an equally long Fabry-Perot laser. Our findings extend classical EIT analogues from passive spectral phenomena to active laser operation.
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All authors Yaoyao Liang, Xinyue Wang, Hongyi Tian, Yulong Fan, Qi Qin, Feihu Wang

Optics

Role of Spatial Coherence in Single-Shot Lensless Image Reconstruction

Ganesh M. Balasubramaniam, Xiao-Liu Chu and Matthew R. Foreman

Lensless imaging is a technique that recovers object information computationally from diffraction patterns recorded without imaging optics, making its performance strongly dependent on the forward model used during image reconstruction. A common source of reconstruction error is the assumption of fully coherent propagation, even when the illumination exhibits partial spatial coherence in practice. Here, the role of spatial coherence is examined for assorted object classes using a coherence-aware forward model based on generalised van Cittert-Zernike Schell propagation. Simulated measurements are generated over a controlled range of effective source spatial coherence lengths and reconstructed using either a partially coherent forward model or a conventional coherent propagation model. Our results show that decreasing spatial coherence progressively degrades reconstructions under the coherent assumption, whereas incorporating partial coherence can preserve object structure and improve image quality, particularly for dense high-spatial-frequency features. Reconstructions from experimental measurements further confirm the practical need to use coherence-aware inversion under partially spatially coherent illumination. These findings establish spatial coherence as a defining component of the inverse problem in lensless imaging and provide a route to optimization of partially coherent lensless imaging systems.
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