Soft Condensed Matter
Lipid Controlled Non-Monotonic Assembly and Rheology of an Egg Yolk Protein at Water-Soybean Oil Interface
Nancy Jaglan, Rumal Singh and Sajal K Ghosh
An essential component of food items like mayonnaise and salad dressing is hen egg yolk. Phosvitin (PVT) is a phosphoprotein, which exists in the granules of this hen egg yolk which stabilizes the food emulsion by preventing phase separation. To understand, how this
protein is adsorbed at the interface of water and edible oil in the presence and absence of lipids is essential for improved control in food production. To monitor the kinetics of this adsorption, the dynamic interfacial tension has been determined in the current investigation. The drop in interfacial tension over time indicates the adsorption of
protein at interface which is enhanced on increasing the concentration of
protein in water phase. However, at higher concentration, the positive activation energy hinders the adsorption process resulting a saturated interfacial tension. The dilation rheology of the macromolecular film at this oil-water interface shows the elastic nature of the film to be greater than the viscous nature, indicating the formation of a soft gel film. At low concentration, the zwitterionic lipid, 1-palmitoyl-2-oleoyl-sn-glycero 3-phosphocholine (POPC), promotes this
protein adsorption at the interface. Interestingly, at high concentration, the lipid overtakes the interface removing the
protein from there. The lipid-
protein composite film again shows the nature of a soft gel. The non-monotonic effects of lipids on assembly of
protein at the water-edible oil interface is an important observation to optimize the composition of relevant food products.
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General Relativity and Quantum Cosmology
A Nonsingular Logarithmic Bouncing Cosmology in $f(R,T)$ Gravity with Thermodynamic Viability
Anjani, Pankaj Kumar, S.H. Shekh et al. (+1 more)
We present a nonsingular bouncing cosmological model in the framework of modified $f(R,T)$
gravity within a spatially flat Friedmann–Robertson–Walker universe. A logarithmic time-dependent scale factor is assumed to realize a smooth transition from a contracting phase to an expanding phase without encountering an initial singularity. Based on this assumption, the dynamical
evolution of the Hubble parameter, deceleration parameter, energy density, and pressure is obtained for various choices of the model and the matter–geometry coupling parameter to confirm the occurrence of a successful bounce. The effective equation of state parameter is examined to characterize the
cosmic fluid during different evolutionary phases. The violation of energy conditions, necessary for the realization of the bouncing behavior, is also discussed. The stability of the model is investigated using the squared speed of sound and is found to remain positive within the allowed parameter space, indicating classical stability. Furthermore, constraints on the matter–geometry coupling parameter are obtained by demanding positive energy density, negative pressure, and a viable cosmological
evolution. The obtained cosmological constraint on the coupling parameter is also shown to be compatible with the currently available compact-object constraints. The thermodynamic behavior of the model is examined by testing the generalized second law of thermodynamics. The total
entropy production rate remains negative during the contracting phase and changes its sign to positive during the expanding phase. However, it becomes singular at the bouncing point, reflecting the breakdown of the standard thermodynamic description during the transition phase.
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All authors Anjani, Pankaj Kumar, S.H. Shekh, Milan Srivastava
General Relativity and Quantum Cosmology
Vishveshwara's waveform revisited: insights from a Keldysh quasinormal mode expansion
Jérémy Besson and José Luis Jaramillo
We revisit Vishveshwara's linear scattering on a Schwarzschild black hole to study the
evolution of quasinormal mode activation along the full time-domain waveform. Specifically, by adopting a hyperboloidal approach we cast the scattering problem in a non-selfadjoint dynamics setting where a (Keldysh) resonant expansion in a bi-orthogonal system of quasinormal modes can be readily performed. The calculation reveals the neat correlation of the second peak in Vishveshwara's waveform to the fundamental mode and first overtones, closely following the ringdown waveform pattern of non-linear evolutions. The first peak is completely controlled, for even (Zerilli) perturbations, by the algebraically special mode and the nearby branch cut. This phenomenon is absent for odd (Regge-Wheeler) perturbations. These qualitative features are robust under change of initial data, extending to Reissner-Nordström and Kerr black holes but being absent when departing from asymptotic flatness to spacetime asymptotics without a branch cut. Underlying linear mechanisms might shed light on the role of algebraic speciality in the transition to the ringdown in non-linear evolutions.
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Instrumentation and Detectors
Usage of GPUs for ALICE Run 3 Offline Reconstruction on the GRID
David Rohr for the ALICE Collaboration
ALICE, the dedicated heavy ion experiment at the LHC, records Pb-Pb collisions at an interaction rate of up to 50 kHz. It was the first LHC experiment to leverage GPUs for online data processing during LHC Runs 1 and 2, and its Run 3 online data processing is now fully based on GPUs with more than 90% of the compute load offloaded to the accelerator. In order to use its online processing server farm also for offline processing in an efficient way while the LHC is not operating, ALICE has been running the offline TPC tracking on GPUs since 2023. Since then, ALICE has been conducting an ongoing effort to offload more offline reconstruction steps to GPUs, and to use the GPUs at other GRID sites beyond the ALICE online computing farm for offline reconstruction. In particular, porting the track model decoding and ITS tracking to GPU has improved the throughput by 29%. In 2026, ALICE ran the first GPU reconstruction jobs on the NVIDIA GPUs of the NERSC Perlmutter cluster, marking the first use of GPUs for LHC offline reconstruction on the GRID. Users can submit GPU reconstruction jobs by specifying only the required GPU count and type, while the underlying infrastructure handles all remaining configurations transparently.
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Quantum Physics
Quantum Inequalities from the Second Law
Andrea Palessandro
Quantum field theory allows local violations of the classical energy conditions, such as regions of negative energy density. The Ford-Roman
quantum inequalities quantify how negative these regions can be and for how long. We present a derivation of these inequalities from the second law of thermodynamics, in an operational framework that couples the field to a small thermal detector. The detector acts as a physical probe of the field's energy density and, by the non-negativity of the
entanglement entropy between the two systems, one can show that its heat loss is bounded from below by a state-independent quantity.
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High Energy Physics (Phenomenology)
The decay properties of two- and three- gluon glueballs
Wei-Han Tan, Hua-Xing Chen, Ding-Kun Lian et al. (+1 more)
We previously studied the decay properties of two- and three-
gluon glueballs using the Fierz rearrangement method and obtained their relative branching ratios in Ref.~\cite{Tan:2026uue}. In this work, we extend and develop this analysis by providing a more complete treatment of two-
gluon glueball decays and by considering the tensor and pseudotensor states with $J^{PC}=2^{++}$ and $2^{-+}$. We also perform an independent QCD sum rule analysis of the $0^{++}$ two-
gluon glueball decay. The consistency between the two approaches provides a useful check of the Fierz analysis. Our results support a sizable
gluon component in the $f_0(1710)$ and favor the $0^{-+}$ glueball interpretation of the $\eta(2370)$. For the tensor glueball, the vector–vector ($VV$) decay channels, especially $K^{*}(892)\bar{K}^{*}(892)$, are found to be favorable for experimental searches. We also study three-
gluon glueballs with $J^{PC}=0^{++}$ and $1^{+-}$ and identify several potentially favorable three-
meson decay channels, including $\pi\pi\omega$ and $K\bar K\phi$. These results provide possible guidance for future experimental searches for glueball states.
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All authors Wei-Han Tan, Hua-Xing Chen, Ding-Kun Lian, Wen-Ying Liu
Mathematical Physics
Confinement transitions in half-space constrained Riesz gases
Sung-Soo Byun, Yong-Woo Lee and Eui Yoo
We study a Riesz gas with interaction parameter $s \in (d-3,d)$ in an arbitrary spatial dimension $d$, confined to a half-space by a hard wall. We prove that the
equilibrium measure exhibits a dichotomy according to the interaction range. For $s \in (d-2,d)$, corresponding to the weakly long-ranged regime, the
equilibrium measure always retains a non-trivial bulk component and thus is never completely confined to the wall. In contrast, for $s \in (d-3,d-2]$, corresponding to the strongly long-ranged regime, a confinement transition occurs: there exists a critical wall position beyond which the
equilibrium measure is supported entirely on the wall. Our
theorem generalises recent results established for the Coulomb gas, corresponding to the case $s=d-2$.
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Materials Science
Data-Efficient Adaptation of DPA-4 Force Fields to DFT+U Energetics: A Case Study in NiO
Fengyu Xie, Peiheng Jiang and Zhicheng Zhong
Foundation machine-learned force fields (MLFFs) are often pretrained on broad materials
datasets whose electronic-structure conventions may not reproduce the phase energetics required for a specific correlated material. Using NiO as a case study, we examine whether incorrect source-level phase energetics can be corrected efficiently through target-level fine-tuning. Along a common structural interpolation, non-
spin-polarized PBE and
ferromagnetic PBE+U predict opposite energetic orderings of the octahedral Oct and square-planar Sqr phases. Pretrained DPA-4 models adapt rapidly to the NiO PBE+U surface, reaching energy and force root-mean-square errors (RMSEs) of approximately 0.5 meV/atom and 30 meV/Å, respectively, with approximately 170 PBE+U labels. Crucially, models previously fine-tuned to the opposing no-U surface recover the qualitative PBE+U phase ordering with nearly the same target-data efficiency as models fine-tuned directly from their respective pretrained initializations. Our results show that incorrect source-level phase energetics can be reversed through target-level fine-tuning, and suggest a practical multi-fidelity strategy in which pretraining prioritizes broad, consistent, and affordable data, while compact target-level
datasets impose energetics through application-specific fine-tuning.
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Quantum Physics
Continuous-variable state moments from randomized homodyne and heterodyne measurements
Michael Tsesmelis, Moritz Straeter and Leong-Chuan Kwek
Continuous-variable (CV)
quantum states are naturally characterized by their moments, defined as expectation values of products of single- or multimode ladder operators. Many CV
Hamiltonians and
quantum algorithms are formulated directly in terms of these moments, and therefore an efficient procedure to estimate moments with limited state measurements is necessary. In this paper, we present a protocol for shadow
tomography of moment-generating functions (MGFs) of CV states based on randomized homodyne and heterodyne measurements. The resulting shadows enable an efficient and concurrent estimation of many multimode moments. Our complexity analysis shows that the number of measurements required to estimate a certain moment to a given precision grows exponentially in the order of the moments. Finally, we assess the precision of these moment
estimators by applying them to two tasks: detecting
entanglement in both Gaussian and non-Gaussian states via the Shchukin-Vogel protocol, and characterizing optical loss in a photonic chip. We demonstrate that both tasks can be accomplished with only a few thousand randomized measurements. The small number of required measurements, combined with efficient sample processing, makes our protocol applicable to a wide range of CV simulation tasks.
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Materials Science
Lithography-free patterning of SrTiO$_3$-based two-dimensional electron gases using direct atomic layer processing
Anshu Gupta, Karolis Parfeniukas, Amit Chanda et al. (+5 more)
We present a scalable and lithography-free strategy for the realization of a two-dimensional electron gas (2DEG) in TiO$_2$-patterned SrTiO$_3$ (100) via Al deposition using magnetron sputtering. A 15 nm thick TiO$_2$ layer, deposited by direct atomic layer processing, is employed to spatially define the conducting regions, enabling direct transport measurements without post-growth microfabrication. Upon Al deposition, an insulating AlO$_x$ overlayer is formed, and the region lacking the TiO$_2$ pattern leads to the creation of oxygen vacancies in SrTiO$_3$. These oxygen vacancies act as electron donors, populating the Ti 3$d$ conduction bands and giving rise to a confined 2DEG at the interface. Magneto-transport measurements reveal a sheet carrier density on the order of $\approx5-7\times10^{13}$ cm$^{-2}$, comparable to values typically achieved in pulsed
laser deposition-grown SrTiO$_3$-based
heterostructures, along with effective electrostatic tunability. This work demonstrates a simple, cost-effective, and industry-compatible route for engineering
oxide 2DEGs, providing a versatile platform for scalable device fabrication and interfacial transport studies.
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All authors Anshu Gupta, Karolis Parfeniukas, Amit Chanda, Thor Hvid-Olsen, Mira Baraket, Maksym Plakhotnyuk, Kasper S. Pedersen, Felix Trier
Optics
Spatial coherence enabled sensorless adaptive optical imaging
Pranay Mohta, Shaurya Aarav, Hugo Defienne et al. (+1 more)
Optical aberrations degrade imaging performance in label-free microscopy, where the absence of a guide
star often necessitates sensorless adaptive optics (AO). Conventional sensorless AO approaches rely on image-quality metrics whose optimal choice depends on both the specimen and the imaging modality. Here, we present a guide-
star-free AO framework based on the spatial coherence properties of spatially incoherent light. The proposed method exploits aberration-induced broadening of the measured spatial correlation distribution as the feedback signal for aberration correction. Experiments in a conventional bright-field imaging system using standard LED illumination demonstrate successful correction of phase aberrations. Furthermore, the approach remains effective even in the presence of spatially structured background noise. These results establish spatial coherence measurements as an effective feedback mechanism for sensorless AO and indicate that the correlation-based feedback principle employed in
quantum-assisted AO can likewise be realized using the spatial correlations of incoherent light.
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All authors Pranay Mohta, Shaurya Aarav, Hugo Defienne, Anand K. Jha
High Energy Physics (Experiment)
A determination of the backscattering probability of low-energy antiprotons
GBAR Collaboration: K. Park, E. Perez, P. Adrich et al. (+41 more)
It is commonly assumed that antiprotons impinging on a material surface annihilate promptly with the
nuclei of the material. However, at kinetic energies of a few keV, this assumption may not hold. As with low-energy
protons, electrons or positrons that can be reflected from a target, they may undergo large-angle Coulomb scattering before annihilation occurs, thereby appearing to be "backscattered" from the material surface. This backscattering fraction, largely unknown, is a crucial ingredient to the determination of the production cross-section of antihydrogen atoms in the GBAR experiment. This paper presents a determination of the probability that 4 and 6 keV antiprotons backscatter on the surface of a Micro-Channel Plate detector used for beam imaging at GBAR. No evidence for backscattering has been found and an upper limit of 14% at 68% confidence level has been set on this probability. The impact of backscattering on the determination of the number of antiprotons that participate in antihydrogen production in GBAR is also addressed.
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All authors GBAR Collaboration: K. Park, E. Perez, P. Adrich, I. Belosevic, P. Cladé, M. Chung, P. Comini, P. Crivelli, P. Debu, A. Douillet, S. Geffroy, S. Guellati-Khelifa, P. Guichard, P.-A.Hervieux, L. Hilico, P. Indelicato, S. Jonsell, J.-P. Karr, B. Kim, S. Kim, E.-S. Kim, N. Kuroda, B. Lee, L. Liszkay, D. Lunney, G. Manfredi, B. Mansoulié, V. Martimort, M. Matusiak, V. Nesvizhevsky, F. Nez, N. Paul, P. Pérez, C. Regenfus, C. Roumegou, J.-Y. Roussé, F. Schmidt-Kaler, K. Szymczyk, T. A. Tanaka, B. Tuchming, D.-P. van der Werf, D. Won, S. Wronka, P. Yzombard
High Energy Physics (Theory)
Algebraic versus physical uniqueness of MHV gravity numerators
Lin Mai and Yaobo Zhang
We study whether a tree-level MHV
gravity numerator is determined by its degree and by vanishing on $\langle ij\rangle=[ij]=0$ for every pair. A flag-variety standard-monomial basis and an $S_n$-resolved restriction map reduce the problem to exact finite-dimensional calculations. At seven points we find $W_{7,\mathbb{Q}}\simeq S^{(2,1^5)}\oplus S^{(1^7)}$. The Hodges numerator spans the sign summand, while the six-dimensional hook gives additional algebraic solutions. The pair-ideal conditions therefore do not determine a unique algebraic solution, but Bose
symmetry selects the Hodges line. At eight points, pair-ideal conditions and Bose
symmetry leave a two-dimensional alternating space. Same-helicity BCFW scaling, normalized collinear factorization, and the leading soft coefficient impose the same linear condition and select the Hodges line. We also prove that, at arbitrary multiplicity, an alternating fixed-degree numerator is determined by its full value on one collinear boundary with the marked legs and their spinor ratio fixed. Together with standard factorization, this determines the numerator up to normalization within the fixed-common-denominator ansatz. All rank and ideal-membership calculations use exact integer or rational arithmetic, and their finite-dimensional consequences are checked separately in Lean.
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Quantum Physics
Antibunching Enhancement via Non-Markovianity in a Hybrid Optical-Microwave Cross-Cavity
Shiying Gu, Jun-Qi Li and Liping Guo
Unconventional
photon blockade (UPB) provides an attractive route for generating antibunched light through
quantum interference without requiring strong nonlinear coupling. In conventional Markovian systems, irreversible dissipation progressively destroys the phase coherence, even limiting the achievable single-
photon purity. Here we propose a scheme for imposing non-Markovian effects on a microwave cavity where a Er$^{3+}$:Y$_2$SiO$_5$
crystal loaded into a hybrid optical-microwave system. Based on the time-convolutionless non-Markovian framework, we derive the time-dependent non-Markovian decay rate and the renormalized microwave drive in the weak-coupling regime. We show that the second-order correlation function is significantly suppressed, even to the order of $10^{-7}$, since the backflow of environmental information enhances
photon blocking. In addition, this structured reservoir engineering not only provides an additional degree of freedom, but also further optimizes the blockade via optical detuning. Importantly, the delayed second-order correlation exhibits a broadened antibunching profile, thereby relaxing the timing requirements for single-
photon synchronization. Our results demonstrate that environmental non-Markovianity can be transformed from a source of decoherence into a controllable
quantum resource, opening new opportunities for high-purity single-
photon generation.
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Earth and Planetary Astrophysics
Infrared-to-visible albedo ratio of Phobos: Comparison with primitive asteroids
T.J. Dyer, J. Beccarelli, M. Delbo et al. (+5 more)
Aims. The ratio between infrared and visible albedo, pIR/pV, provides a simple proxy for the spectral slope of asteroid surfaces between the visible and near-infrared wavelength ranges. The aim of this work is to assess whether the different spectral units of Phobos occupy the same spectral parameter space as the primitive asteroid populations in order to confirm or not its possible asteroidal origin. Methods. For each of the three spectral units of Phobos (Red, Transitional and Blue), we extracted averaged, normalised reflectance spectra by comparing normalised reflectance in the visible (0.50-0.60 $\mu$m) and near-infrared (3.1-3.8 $\mu$m) wavelength ranges from the Mars Express OMEGA instrument, to compute a proxy for the infrared-visible albedo ratio ($R_P$). Then, using the database of visible and infrared albedos compiled in the Minor
Planet Physical Properties Catalogue (MP3C), we computed asteroid pIR/pV values ($R_A$), to compare to those for Phobos. Results. The $R_P$ for the Red, Transitional and Blue regions vary between 2.90 and 3.12, 2.32 and 2.35, 1.64 and 1.85 respectively. These values span a range occupied by primitive asteroid populations, with the Transitional and Red regions coinciding with the high ratio regime within the pIR/pV domain, which is commonly associated with red-sloped primitive asteroids, including D- and T-type objects as well as Jupiter Trojans.
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All authors T.J. Dyer, J. Beccarelli, M. Delbo, C. Avdellidou, M. Pajola, A. Milton, A. Lucchetti, G. Munaretto
Optics
Aggregation-engineered loss-tolerant strong coupling in metallic microcavities
Andrea Betti, Eleonora Cara, Giulia Serrano et al. (+7 more)
Room-temperature strong coupling in organic microcavities is usually achieved by combining high-quality optical resonators with highly ordered excitonic media, a requirement that limits scalability and processing flexibility. Here we show that this constraint can be relaxed by using molecular aggregation as a design parameter rather than treating it as a parasitic effect. We realize solution-processed Rhodamine 6G-poly(vinyl alcohol) films embedded in low-quality-factor silver Fabry-Perot microcavities and demonstrate clear angle-resolved anticrossing with coupling energies up to 324 meV despite the large optical losses of the metallic mirrors. A two-
exciton coupled-oscillator model shows that the relative weight of these species controls the collective coupling strength and can be tuned through dye loading and
spin-coating conditions. In contrast, angle-resolved photoluminescence is dominated by a broad, red-shifted lower-polariton emission, consistent with relaxation through excimer-like states formed in densely packed molecular domains. These results identify molecular aggregation as a practical design lever for loss-tolerant strong coupling in wet-processed metallic cavities and suggest that ground-state aggregates and excited-state excimer-like species play distinct roles in polariton formation and emission.
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All authors Andrea Betti, Eleonora Cara, Giulia Serrano, Lorenzo Poggini, Alessia Valzelli, Natascia De Leo, Paolo Bartolini, Andrea Taschin, Renato Torre, Alice Boschetti
Strongly Correlated Electrons
Spin nematic liquid crystal and scalar spin chirality in tetragonal lattice YbMnBi$_2$
Yaofeng Xie, Sijie Xu, Yu Pan et al. (+22 more)
A
spin nematic order, analogous to the nematic
liquid crystal, characterizes the spontaneous breaking of
spin-space rotational
symmetry while preserving time-reversal ($T$)
symmetry. In contrast, scalar
spin chirality (SSC), a composite three-
spin order, breaks $T$
symmetry and is known to induce an anomalous
Hall effect (AHE). Although a
spin nematic phase has been suggested in frustrated magnets and the square-
lattice iridate, how it might affect magnetotransport properties is unknown. Here we use polarized
neutron scattering to show that tetragonal $A$MnBi$_2$ ($A$ = Ca, Yb) is a strictly $c$-axis-aligned collinear antiferromagnet (C-type), with $T_N \approx 270$ K and 290 K, respectively. On cooling from 450 K to $T_N$, low-energy
spin excitations in YbMnBi$_2$ spontaneously change from isotropic to anisotropic in
spin space within the tetragonal plane, forming a dynamic
spin nematic phase around 400 K due to heavy Yb-induced
spin-orbit coupling, before gapping out below $T_N$. Similar measurements on CaMnBi$_2$ reveal isotropic paramagnetic scattering without a
spin nematic phase above $T_N$. Under an in-plane
magnetic field, the Yb$^{3+}$ moments may interact with the dynamic
spin nematic phase to induce nonzero SSC, giving rise to AHE and an anomalous Nernst effect (ANE) in YbMnBi$_2$ that are absent in CaMnBi$_2$ above $T_N$. A
symmetry-based Ginzburg-Landau analysis shows that coupling terms between the nematic order and SSC are allowed under an external
magnetic field, which could explain the rapid increase of AHE with field in YbMnBi$_2$. Our results provide compelling evidence for dynamic SSC-induced AHE and ANE in the paramagnetic phase of a compensated collinear antiferromagnet, opening a new avenue for the physics of composite
spin orders and room-temperature spintronics without
magnetic order.
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All authors Yaofeng Xie, Sijie Xu, Yu Pan, Taekoo Oh, Tingjun Zhang, Masaaki Matsuda, Zhaoyu Liu, Zehao Wang, Yiheng Wang, Siyu Pan, Avishek Maity, Sylwia Pawledzio, Xiaoping Wang, Songxue Chi, Feng Ye, Yiqing Hao, Huibo Cao, Barry L. Winn, Melissa K. Graves-Brook, Shuai Wu, Fan Li, Xiaoyuan Zhou, Claudia Felser, Naoto Nagaosa, Pengcheng Dai
High Energy Astrophysical Phenomena
Radio flares and X-ray hardening embedded in the long soft state of 4U 1543-475
Zuobin Zhang, Rob Fender, Jiachen Jiang et al. (+14 more)
We present a comprehensive multi-wavelength study of the black hole X-ray binary 4U 1543-475 during its 2021 outburst, focusing on
radio flaring episodes that are commonly interpreted as signatures of episodic jet production and are embedded within states when the X-ray emission was dominated by an
accretion disk component. The
radio monitoring reveals at least two discrete
flares that coincide with periods of enhanced Comptonized X-ray emission. Broadband spectral modelling shows a significant decrease in the reflection-to-disk flux ratio (by a factor of ~3-4) during these episodes, consistent with a temporary change in the geometry of the inner
accretion flow, although the data do not allow the causal sequence to be firmly established. Optical photometry exhibits variability that broadly tracks the reflection fraction, consistent with changes in the illuminating component. The accompanying spectral hardening indicates that the
radio flares were associated with short-lived excursions toward a "harder" state, departing from the soft state. X-ray timing analysis suggests that the
radio flares may be associated with changes in the fractional rms variability; however, no consistent or unified pattern can be firmly established across different events. These results provide a multi-wavelength observational example of
radio flaring activity in a black hole binary and highlight the complex interplay between
accretion flow geometry, coronal emission, and jet-related phenomena.
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All authors Zuobin Zhang, Rob Fender, Jiachen Jiang, Payaswini Saikia, David M. Russell, Andrew Hughes, Honghui Liu, Francesco Carotenuto, James F. Steiner, Fraser J. Cowie, John A. Tomsick, Cosimo Bambi, Yimin Huang, Xian Zhang, Wenfei Yu, Yuexin Zhang, Rittick Roy
Materials Science
Advancing in situ hydrogen embrittlement studies through an integrated charging cell for SEM micromechanical testing
Lavakumar Bathini, Guillaume Kermouche, Sergio Sao-Joao et al. (+2 more)
A comprehensive understanding of hydrogen-deformation interactions at the microscale is essential for revealing hydrogen embrittlement mechanisms. In situ micromechanics with simultaneous hydrogen (H-) charging has therefore gained traction in recent times. In the present study, we aim to address the drawbacks of current in situ H-charging setups by developing a more robust 3-electrode-based back-side charging system for a scanning electron microscope to perform various micromechanical tests. The development of the novel setup is discussed and demonstrated through micropillar compression of an Fe-25Cr single
crystal (110) during H-charging. H has increased the yield strength and the apparent strain-hardening rate. H activates multiple slip systems and enhances dislocation density and
entanglement, leading to pronounced forest hardening as revealed by electron microscopy. Estimation of activation volume from strain-rate jump tests indicates that the deformation is controlled by the solute drag effect on kink mobility and dislocation forest hardening.
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All authors Lavakumar Bathini, Guillaume Kermouche, Sergio Sao-Joao, Frédéric Christien, Szilvia Kalácska
High Energy Astrophysical Phenomena
Cherenkov light as a mechanism for light flashes seen by astronauts in space
Dominika Švecová, Pavol Bobík and Blahoslav Pastirčák
Astronauts first reported light flashes during the Apollo 11 mission. These events have since been associated with
cosmic rays, although their underlying mechanism remains uncertain. This study investigates possible formation processes using Geant4 simulations of
cosmic ray interactions in a simplified model of the human eye. We apply published models of human visual perception to the simulated particle induced
photons and compare the resulting light flash rates with experimental observations. Our results indicate that, in interplanetary space and in low Earth orbit outside the South Atlantic Anomaly, Cherenkov radiation generated in the eye produces retinal responses consistent with the observed frequency of astronaut light flashes. The dominant contributing primaries are found to be high Z
nuclei, primarily iron, with additional contributions from oxygen and carbon
nuclei. In contrast, conditions in the South Atlantic Anomaly suggest that additional mechanisms may be required to explain observed light flashes. We also find that the absence of light flashes at Earth's surface is consistent with insufficient retinal stimulation from
muon induced Cherenkov radiation under typical geometrical and flux conditions.
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Applied Physics · Cross-listed from cs.CV
Automated binary classification of hazelnut X-ray images: A deep-learning benchmark for quality assessment
Giancarlo Sportelli, Nicola Belcari, Roberta Pace et al. (+4 more)
Non-destructive X-ray imaging can reveal internal hazelnut defects that are difficult to detect by external inspection alone; however, automated interpretation remains challenging because of subtle radiographic differences among classes, marked class imbalance, and limited annotated data. Here, we present a
benchmark for binary hazelnut quality classification (healthy versus defective) based on 799 segmented single-kernel X-ray images (224 x 224 pixels, grayscale), grouped into 101 acquisition units. Seven single-model configurations and ten probability-aggregation ensembles were evaluated using a group-wise split-rotation protocol across five data splits generated using different random seeds. Decision thresholds were selected on the validation set, and performance was assessed deterministically on validation and test sets. Under the expert-reassessed annotation condition, the average-probability ensemble of the binary cross-
entropy-trained convolutional neural network and frozen Swin
Transformer achieved the highest mean balanced accuracy (86.3% +/- 1.8%, five seeds), with several other ensembles providing comparable performance. Across methods, substantial split-to-split variability was observed, indicating that multi-split evaluation is essential for reliable model comparison at this
dataset scale. Expert reassessment of ambiguous samples improved the performance of all 17 evaluated methods by 2.8-8.1 percentage points, while having only a limited effect on cross-split variance. The results highlight both the potential of deep learning for automated X-ray-based hazelnut quality assessment and the importance of rigorous evaluation and label curation in small, imbalanced agricultural imaging
datasets.
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All authors Giancarlo Sportelli, Nicola Belcari, Roberta Pace, Umberto Bernardo, Sharmin Sultana, Alessandra Toncelli, Matteo Giaccone
Optics
Origin, strength, and speed of the nonlinear optical response of transparent conducting oxides to single-cycle optical pulses
Ieng-Wai Un, Subhajit Sarkar and Yonatan Sivan
We present a first-principles study of the nonlinear optical response of transparent conducting
oxides at the nanoscale due to excitation by intense, extremely short pulses based on a density
matrix framework. We identify a strong ($O(1)$) thermal nonlinearity, which is complemented with stimulated emission and excited-state absorption; it yields a cumulative permittivity change decorated by
quantum coherent oscillations. Further, rigorous calculations under far-from-
equilibrium conditions show that electron-electron thermalization occurs within a few femtoseconds, supporting interpretations of high-harmonic generation measurements and in agreement with a generalization of
Fermi liquid theory.
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Strongly Correlated Electrons
Light-induced effective magnetic fields in Landau quantized graphene
Hiroki Ueda, Alexej Pashkin, Ece Uykur et al. (+6 more)
Ultrafast magnetism triggered by circularly polarized radiation underpins ultrafast
spin control, relevant to future technologies, e.g., opto-spintronics and magnonics. The dynamics are often complicated and intertwined among correlated subsystems, such as electrons,
spins,
phonons, plasmons,
topology, and
lattice, due to many-body
quantum coupling at ultrafast timescales. Here, we demonstrate light-induced effective
magnetic fields generated by selective excitation between non-equidistant Landau quantized states in
graphene, a prototypical Dirac material, using circularly polarized pulses. By magnetically tuning the Landau-level transition resonance away from other low-energy excitations, we obtain a clean electrostatically controllable platform and identify the microscopic origin of the light-induced
magnetic signals, independent of sublattice coupling. Because different Landau levels carry distinct optical
Hall conductivities, direct modification of their occupancies via optical excitations creates transient Faraday rotation signals with dispersive
magnetic-field dependence, mirroring the static magneto-optical lineshape. The induced effective
magnetic field normalized by the pump electric field exceeds typical reported values for the inverse Faraday effect of electronic origin. Our results establish a clear microscopic picture of the inverse Faraday effect of electronic origin, which can trigger hierarchical dynamics among correlated sublattices once Landau-level transitions are magnetically tuned to coincide with other low-energy excitations in Dirac systems and related materials.
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All authors Hiroki Ueda, Alexej Pashkin, Ece Uykur, Kryštof Kašša, Filip Chudoba, Jan Kunc, Manfred Helm, Milan Orlita, Stephan Winnerl
Mesoscale and Nanoscale Physics
Magnetic noise of a dark exciton Bose-Einstein condensate
Pieter M. Gunnink
Excitons provide a promising platform for the realization of solid-state Bose-Einstein condensation (BEC), offering
quantum coherence, strongly correlated electron-hole physics, and superfluidity. Yet, its unambiguous experimental identification remains challenging. In particular, $S_z= \pm 1$ triplet
excitons are excellent candidates to realize an
exciton BEC, because of their intrinsically limited recombination rate and thus long lifetimes. However, since their optical detection is inherently forbidden, experimental signatures remain elusive. In this work, we demonstrate that the
magnetic nature of a $S_z= \pm 1$ triplet
exciton BEC gives rise to stray
magnetic field noise, that can be measured using nitrogen-vacancy (NV) center magnetometry. Using an external
magnetic field to tune the system from an
antiferromagnetic to a
ferromagnetic ordering, the longitudinal
spin sound mode of the BEC softens, bringing the mode into the characteristic gigahertz frequency range of the NV
spin relaxation rate and thus allowing direct detection. Furthermore, we demonstrate an unconventional UV scaling at small distances $d$ from the sample, owing to the cubic corrections to the sound mode dispersion and damping rate in the form of Beliaev damping. Through this approach, we establish that the
spin component of
exciton BECs offers new approaches to detect
exciton BECs.
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Quantum Physics
A 12-CNOT Double Qubit Excitation Gate
Irfansha Shaik
Effective implementation of high-level
quantum gates is essential for practical
quantum computing. In this work, we presented, to the best of our knowledge, the first reported 12-CNOT decomposition of the double
qubit excitation operator. We compared our new
circuit with the previous SOTA 13-CNOT
circuits in 4 different metrics. Our new
circuit has the lowest CNOT count (12), lowest CNOT depth (8, roughly 27% reduction), and lowest total
circuit depth (15, 25% reduction) among all the previous SOTA
circuits. With output
qubit relabeling, the CNOT depth can be further reduced to 7 (roughly 36% reduction from 11). Further, we only added 2 extra 1q gates (from 11 to 13) compared to the best of the SOTA
circuits. As the double
qubit excitation operator can be used as a building block hundreds or thousands of times in practical
quantum algorithms, any reduction in such primitives compounds over the full
circuit, resulting in significant overall resource savings.
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Astrophysics of Galaxies
Molecule-specific diffusion and desorption of interstellar ices on carbonaceous dust
Yi-Hsuan Chiu, Tushar Suhasaria, Cornelia Jäger et al. (+4 more)
Interstellar ices form on
dust grains in the coldest regions of molecular clouds and preserve key volatile reservoirs that could be incorporated into protoplanetary disks during
star and
planet formation. However, the effect of the
dust surface composition on the ice structure and spectroscopic behavior remains poorly constrained. We present a comparative laboratory study of astrophysically relevant ices (CO, CO2, and H2O) deposited on inert calcium fluoride (CaF2) substrate and carbonaceous
dust analogs under interstellar conditions. Infrared spectroscopy and temperature-programmed desorption reveal pronounced molecule-specific infrared spectral responses to the amorphous carbonaceous surface. CO and CO2 both exhibit broadened absorption bands, redshifted band positions, and delayed desorption, arising from thermally activated
diffusion into the porous
dust matrix and indicating strong molecule-surface interactions. By contrast, H2O varies only very little spectrally and thermally, indicating weak wetting and limited coupling to the substrate. These results provide direct laboratory evidence that
dust-ice interfaces can affect the ice structure and desorption kinetics of interstellar ices even in thick ice layers. These findings offer new constraints for interpreting infrared absorption bands in astronomical observations and highlight the importance of surface effects in models of interstellar ice chemistry.
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All authors Yi-Hsuan Chiu, Tushar Suhasaria, Cornelia Jäger, Chun-Yi Lee, Ko-Ju Chuang, Thomas Henning, Yu-Jung Chen
Mathematical Physics · Cross-listed from math.SP
Quantum mixing for eigenfunctions of rational polygons in configuration space
Kai Hippi and Søren Mikkelsen
The Shnirelman-Zelditch-Colin de Verdière
theorem and its weak mixing extension relate
quantum ergodicity and
quantum mixing with ergodicity and weak mixing of the geodesic flow. Integrable systems, such as the flat
torus, do not satisfy either in general. Restricting to position-dependent observables, Marklof and Rudnick established equidistribution for almost all eigenfunctions of rational polygons. In this note, we extend this result to off-diagonal elements for a subset of rational polygons not including the
torus using weak mixing of the directional billiard flow for almost all directions. Additionally, we provide a different proof that establishes the same result for $2$-
tori.
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Materials Science
Deep-Learning-Accelerated Dopant Selection for High-k HfO2 Dielectrics: A Disorder-Resolved Study of Y, Si and Al
Zunair Masroor, Bonwook Gu, Wonjoong Kim et al. (+3 more)
Hafnium
oxide (HfO2) is the cornerstone high-k dielectric in modern silicon technology. Since the constraints of silicon device fabrication rule out replacing the material itself, dopant incorporation is the principal means available to engineer its band gap and dielectric constant within existing process flows. However, dopant selection is still largely empirical due to the coupled interplay among thermodynamic stability, electronic insulation, and dielectric response. Here, we present a high-throughput computational framework integrating special quasi-random structures (SQS), machine-learning potentials (SevenNet), and graph neural networks (ALIGNN) to systematically evaluate doped-HfO2 compositions across three dopants (Al, Si, Y) and two technologically relevant polymorphs (monoclinic and orthorhombic). Our analysis uncovers a fundamental design principle: formation energy, band gap, and dielectric constant are decoupled parameters requiring application-specific prioritization rather than simultaneous optimization. Yttrium achieves the lowest formation energy (-3.763 eV/atom) and favors orthorhombic phase stabilization at process-compatible thermal budgets; silicon preserves near-pristine band gaps (around 5.72 eV) critical for suppressing leakage in gate dielectric applications; and aluminum enables concentration-tunable band gap widening (5.6-5.9 eV) suited for voltage scaling. Validation against experimental literature and density functional theory (DFT) confirms quantitative accuracy (0.02 eV band gap error for Si-doping, mean absolute error less than 0.001 eV/atom formation energy). This framework provides rational, property-decoupled guidance for dopant engineering in HfO2-based dielectrics and related high-k
oxide systems.
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All authors Zunair Masroor, Bonwook Gu, Wonjoong Kim, Trinh Ngoc Le, Summal Zoha, Han-Bo-Ram Lee
High Energy Physics (Theory)
Scalar Finite-Proper-Time Field Theory as a Complete-History Spectral Calculus
Mustafa Bakr and Tongyu Zhang
We formulate a finite-proper-time (FPT) construction for real scalar $\lambda\phi^4$ theory in which a non-zero lower endpoint $s_0$ is retained as physical spectral data for complete virtual histories. Functional differentiation partitions a pre-existing history, while interaction sewing creates closed momentum circulations. Local momentum conservation identifies the primitive closed circulations with graph
circuits; applying the retained endpoint condition gives \[ s_e\ge0, \qquad \sum_{e\in c}s_e\ge s_0 \quad(c\in\mathcal{C}(G)). \] An individual edge or bridge may be arbitrarily short, but no complete closed circulation may collapse below $s_0$. This routing-independent prescription differs from damping every propagator. We prove that it gives a positive loop quadratic form and ultraviolet-finite massive amplitudes, including overlapping short-distance regions. Under a physical cut, precisely the
circuit conditions crossed by the cut disappear, leaving the independently constructed daughter domains together with the ordinary pole residues and positive scalar phase space. At fixed $s_0$ we give an all-order local construction; for $\lambda\ge0$, $\mathcal{K}_{\bar{\phi}}\ge-\partial^2+m^2$ gives a background-uniform heat-kernel bound. The open Euclidean history kernel is virtual spectral machinery rather than the physical propagator, and physical positivity is imposed on complete boundary amplitudes. After local matching, the first non-constant one-loop on-shell correction is proportional to $s_0^2(s^2+t^2+u^2)$, providing a correlated observable test of the retained scale.
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Quantum Physics
Do Not Let CNOTs Overwhelm the Decoder: Scheduling Transversal Gates for Fast FTQC
Shota Ikari, Yuga Hirai, Yasunari Suzuki et al. (+2 more)
Transversal CNOT (TCNOT) gates can accelerate fault-tolerant
quantum computation (FTQC) in the surface code by reducing the number of syndrome extraction rounds required between logical operations from $O(d)$ to $O(1)$. This is particularly attractive for
quantum platforms with long-range connectivity, such as neutral atoms. However, dense TCNOT schedules substantially increase the classical decoding workload. TCNOTs propagate errors across multiple surface-code patches, enlarging the spatiotemporal region that must be decoded jointly. Consequently, denser TCNOT schedules increase decoding latency and
memory requirements and potentially exceed available decoder capacity. Moreover, because the detector error model (DEM) of each decoding window depends on the TCNOT schedule, exhaustively precomputing all possible window-level DEMs is infeasible, requiring just-in-time (JIT) DEM compilation. Thus, the practical benefit of TCNOT gates is limited not only by
quantum hardware performance but also by classical decoding and DEM-compilation capacity. We introduce PACE, a decoder-aware scheduling framework for TCNOT-based FTQC. PACE first mitigates the decoder-side costs of aggressive TCNOT scheduling through three complementary techniques. Hybrid Window Decoding assigns different decoders for each decoding window according to its DEM structure. DEM Stitch generates schedule-specific window-level DEMs just in time by assembling reusable precompiled fragments. Sub-window Parallel Decoding decomposes large windows into smaller sub-windows with graph-coloring formulation. Building on these techniques, PACE then performs decoder-aware scheduling to maximize TCNOT concurrency within the available decoder resources. Our evaluation shows the trade-off between
quantum acceleration and classical decoding cost, revealing the limitations of current decoding systems for TCNOT-based FTQC.
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All authors Shota Ikari, Yuga Hirai, Yasunari Suzuki, Hiroshi Nakamura, Yosuke Ueno