Quantum Gases
Robust quantum-droplet necklace clusters in three dimensions
Liangwei Dong, Dongshuai Liu and Boris A. Malomed
We report the existence of quasi-stable ring-shaped (necklace-shaped) clusters built, in the free space, of 3D
quantum droplets (QDs) in a binary Bose-Einstein condensate, modeled by the Gross-Pitaevskii equations with the Lee-Huang-Yang corrections. The QD clusters exhibit diverse dynamical behaviors, including contraction, oscillations, and expansion, depending on the cluster's initial radius. A phase shift between adjacent QDs imparts net angular momentum to the cluster, inducing its permanent rotation. Through the energy-minimization analysis, we predict
equilibrium values of the necklace radius that support persistent rotation with negligible radial pulsations. In this regime, the clusters evolve as robust entities, maintaining the azimuthal
symmetry in the course of the
evolution, even in the presence of considerable perturbations. Necklace "supervortex" clusters, composed of QDs with inner vorticity 1 and global vorticity M, imprinted onto the cluster, may also persist for a long time. The reported findings may facilitate the experimental realization of complex self-sustained
quantum states in the 3D free space.
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Quantum Gases
Quantum phase transitions of the anisotropic Dicke-Ising model in driven Rydberg arrays
Bao-Yun Dong, Ying Liang, Stefano Chesi et al. (+1 more)
We study the properties of a generalized Dicke-Ising model realized with an array of Rydberg atoms, driven by microwave electric fields and coupled to an optical cavity. As this platform allows for a precisely tunable anisotropy parameter, the model exhibits a rich landscape of phase transitions and critical phenomena, induced by the interplay of rotating-wave, counter-rotating-wave, and Ising interactions. We develop an improved
quantum Monte Carlo
algorithm based on the
stochastic series expansion that explicitly tracks the Fock state of the
quantum cavity. In the superradiant (SR) phase, this allows us to determine, through data collapse, the scaling laws of the
photon number. We also demonstrate the vanishing of parity
symmetry in finite-size simulations and show that the Rydberg blockade leads to a significant suppression of cavity occupation. Notably, stronger
quantum fluctuations induced by the counter-rotating wave terms slightly favor the superradiant solid (SRS) phase over the Solid-1/2 state. Finally, we confirm that the SR phase transition and the transition from the Solid-1/2 to the SRS are second-order. In contrast, the transitions from the Solid-1/2 or SRS to the SR phase are both first-order for any value of the normalized anisotropy parameter.
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All authors Bao-Yun Dong, Ying Liang, Stefano Chesi, Xue-Feng Zhang
Statistical Mechanics
Exact solution for one-dimensional spin models with Markov property
Yu. D. Panov
For one-dimensional
spin and pseudospin models that allow mapping to a Markov chain, the free energy of the system at a finite temperature can be expressed in terms of bond concentrations. Minimizing the free energy function makes it possible to obtain an exact solution of a statistical model. A dilute Ising chain with interacting
impurities is considered as an example.
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Materials Science
Symmetry-Breaking Phenomena in MnPS3/TMDC Heterostructures: Non-relativistic Spin Splitting, Altermagnetism and Spin-Valley Effects
Kamil Wrzos, Magdalena Birowska and Milosz Rybak
We explore
symmetry-breaking phenomena in MnPS3/TMDC (MoS2, WS2, MoSe2, WSe2)
heterostructures using first-principles calculations, considering two high-
symmetry stacking configurations, S1 and S2, which differ not only by their interfacial registry but also by a 30{\deg} twist between the layers. Depending on the stacking geometry, the systems exhibit two distinct types of nonrelativistic
spin splitting (NRSS): S2 hosts altermagnetic-like band crossings, while S1 shows global
spin splitting characteristic of
symmetry-breaking NRSS.
Magnetic exchange and anisotropy parameters indicate that the intrinsic
magnetic properties of MnPS3 are largely preserved upon interfacing. Including
spin-orbit coupling, we find tunable conduction-valley splitting controlled by the MnPS3
spin orientation. Our results identify MnPS3 as a
symmetry-tunable
antiferromagnetic substrate capable of inducing and controlling
spin and valley effects in 2D
heterostructures without relying on net magnetization or strong SOC, offering a route toward nonvolatile valleytronic functionalities.
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Strongly Correlated Electrons
Néel Ordered Magnetic Phases in Bipartite Quasicrystals
Jia-Heng Ji, Zhi-Yan Shao, Yu-Bo Liu et al. (+2 more)
Magnetism is a fundamental research area in which the recently proposed altermagnetism (AM) has become an emergent frontier. Very recently, the quasicrystal (QC) was proposed as a possible platform to realize AM. However, the existence of AM in QCs still lacks vigorous evidence. In this work, we adopt the sign-problem-free projector
quantum Monte Carlo (PQMC)
algorithm to investigate the
magnetic phases in the half-filled Hubbard models in various 2D bipartite QCs, and always obtain Néel ordered states. While the Néel states in bipartite
crystals are usually antiferromagnetism (AFM), we find it common that those in bipartite QCs can also be AM or ferrimagnetism (FIM). Based on
symmetry analysis, combined with our comprehensive PQMC results, we propose a general criterion for determining the magnetism classes of the Néel states in a bipartite QC: According to whether the two sublattices are related by inversion, a non-inversion point-group operation such as mirror or rotation, or no operation about the unique
symmetry center, the corresponding Néel state is AFM, AM or FIM / geometry-enforced AM (G-AM), respectively. The G-AM is a special type of $s$-wave AM caused by the unique QC structure formed through projection from high-dimensional
crystals to lower dimensions, which is rare in
crystals. For example, our results yield
symmetry-protected AM for the two $D_4$-symmetric Thue-Morse QCs and G-AM for the $D_5$-symmetric Penrose QC at half-filling. Our results provide a solid foundation for experimental investigations and potential applications of different classes of magnetism in QCs.
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All authors Jia-Heng Ji, Zhi-Yan Shao, Yu-Bo Liu, Wei Li, Fan Yang
Soft Condensed Matter
Entangled-to-packed crossover in nonlinear extensional rheology of entangled polymers
Yin Wang, Lin-Feng Wu, Yi-Bo Shao et al. (+1 more)
Significant challenges exist in the nonlinear extensional rheology of entangled
polymers. With simulations, we show that the key to understanding this problem is to recognize the existence and importance of a strain-induced crossover from the entangled state to a packed state. This crossover, following the saturation of primitive chain stretch, takes place with massive release of entanglements via convective flow and progressive chain
alignment. After the crossover, the disentangled, fully-aligned chain segments pack similarly to the random packing of rods. Meanwhile, the system enters the steady state. In this state, the tube model, built on the concept of
entanglement, fails, while the stress can be quantitatively calculated by combining the intra-chain conformational contribution and a frictional contribution from the inter-chain separation along flow.
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All authors Yin Wang, Lin-Feng Wu, Yi-Bo Shao, Zhe Wang
Soft Condensed Matter
Complex network analysis of pore structures in monodisperse granular materials with varied grain shapes
Jie Qi, Wenbin Fei and Guillermo A. Narsilio
Understanding how pore structure influences flow and transport behaviour in granular materials is essential for addressing a wide range of geotechnical, hydraulic, and environmental challenges. These processes are largely shaped by the microscopic arrangement of particles and interconnections between pores within the material. However, detailed insights considering granular assemblies with diversified grain shapes remain scarce. This study introduces a comprehensive framework incorporating Discrete Element Method (DEM) simulations, image processing, pore-network modelling, and complex network theory to investigate the links between particle morphology and their hydraulic behaviours. Mono-disperse assemblies of natural sand particles with varied shapes are constructed in DEM, and pore networks are extracted through image processing and pore-network modelling. Complex network analysis is then applied to calculate structural metrics that reveal intrinsic relationships between pore microstructures and hydraulic properties. Our results demonstrate that particle morphology significantly impacts pore network characteristics, including pore and throat sizes, closeness centrality, pore structure anisotropy, providing valuable insights into how pore structure influence transport properties.
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Materials Science
Patterning perovskite colour converters for AR/VR microdisplays
Ruairi Baker, Maria Pervez, Angus Hawkey et al. (+3 more)
Colour conversion offers the clearest path to achieve RGB colours in high resolution microdisplays for AR/VR. With resolutions beyond 5000 ppi (i.e. RGB pitch of 5 um), the thickness of the conversion layers is critical for efficiency and manufacturing. Perovskites outperform other conversion materials (
quantum dots or phosphors) with their high absorption coefficients for blue light. In this contribution, we show how perovskite materials, engineered for high optical density and colour purity, can be patterned to produce colour converting pixels. We demonstrate patterning using three approaches (lift-off, negative photoresist and dry etch), and discuss their advantages and disadvantages. The results consolidate the choice of perovskites for AR/VR applications by demonstrating their robustness and compatibility with multiple patterning strategies suitable for high resolution microdisplays.
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All authors Ruairi Baker, Maria Pervez, Angus Hawkey, Nobuya Sakai, Valerie Berryman-Bousquet, Bernard Wenger
Materials Science · Cross-listed from physics.optics
2D MoS$_2$/Au interfaces for enhanced opto-electronic response with sub-bandgap photons
Jinlei Wu, Wei Huang, Ahsan Ali et al. (+5 more)
Monolayer MoS$_2$ is a direct band gap
semiconductor with potential applications in optoelectronics and photonics. MoS$_2$ also has a large optical nonlinearity. However, the atomic thickness of the monolayer limits the strength of the measured functional signals, such as the photocurrent or photoluminescence, in optoelectronic devices. Here, we show that photocurrent in monolayer MoS$_2$ can be induced by sub-band gap
photons by depositing Au nanoparticles on it. In this system, the nonlinear light-matter interaction in Au nanoparticles enhanced by the localized surface plasmons results in the generation of supercontinuum, which is reabsorbed by MoS$_2$ due to efficient resonant energy transfer. Au nanoparticle assisted photocurrent is more than an order of magnitude larger than two-
photon photocurrent in monolayer MoS$_2$. Optimization of the shape, size and composition of the nanoparticle has the potential to enhance the photocurrent significantly with the prospect of applications in the detection of NIR
photons, and related technologies including optical telecommunication.
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All authors Jinlei Wu, Wei Huang, Ahsan Ali, Yuhong Chen, Elissaios Stavrou, Zuoti Xie, Jinhui Zhong, Khadga Jung Karki
Materials Science
Unraveling UV Stability in Metal Halide Perovskites: From Degradation Mechanisms to Molecular Passivation
Xin Wen, Zhiyi Yao, Wenzhuo Li et al. (+2 more)
Understanding the mechanisms of UV-induced degradation is crucial for enhancing the UV stability of perovskite
solar cells. The UV-driven structural dynamics of CH3NH3PbI3 (MAPbI3) are investigated using real-time TDDFT simulations, revealing that under the electron and hole excitation, the distortion of the inorganic framework (PbI) is primarily driven by the electron occupation of Pb-p and I-p antibonding states, whereas in the hole case, it is mainly governed by the direct cooling induced distortion. We also find that UV accelerates the rotation of MA+ molecules. Further, a BDO molecule is introduced as a passivant, which suppresses structural distortions and provides multi-
phonon channels to dissipate carrier cooling energy. Experimental results confirm the UV-protective role of BDO, with suppressed PbI2 formation and improved device stability. These results clarify the mechanism of the UV-induced degradation in the MAPbI3 perovskite and further elucidate how passivation molecules enhance UV stability.
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All authors Xin Wen, Zhiyi Yao, Wenzhuo Li, Zhijun Ning, Fan Zheng
Strongly Correlated Electrons · Cross-listed from hep-th
Fermionic Non-invertible Symmetry Behind Supersymmetric ADE Solitons
Jin Chen, Zhihao Duan, Qiang Jia et al. (+1 more)
The non-perturbative constraints imposed by intrinsic fermionic non-invertible
symmetries in 1+1 dimensional gapped systems remain largely unexplored. In this letter, we propose the superstrip
algebra as a unified framework to catalog the categorical
symmetry data in a massive fermionic model. The
algebra and its representations explicitly encode the
vacuum structure,
soliton degeneracies, and their
quantum numbers. As a demonstration, we apply this framework to the $\mathcal N=2$ minimal models with their least relevant deformation. We show that this specific deformation alone preserves a non-invertible superfusion category, a fermionic variant of $\text{SU}(2)_k$ known to underlie the $ADE$ classification of critical theories. Its superstrip
algebra then accounts for the origin of the resulting $ADE$-type
soliton spectrum and their fractional
fermion number. Although our primary examples are supersymmetric and integrable, our framework itself relies on neither property, providing a new powerful tool for studying a broad class of strongly-coupled fermionic systems.
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All authors Jin Chen, Zhihao Duan, Qiang Jia, Sungjay Lee
Mesoscale and Nanoscale Physics
Evidence for electron localisation in a moiré-of-moiré superlattice
Hangyeol Park, Junhyeok Oh, Rasoul Ghadimi et al. (+7 more)
The localisation of electrons in a
lattice potential is an
quantum-mechanical phenomenon and is often associated with remarkable physical properties of solids involving electron
spins, electric polarisations and topological effects. In particular, even a small amount of distortion of the
lattice potential can localise otherwise-delocalised
quantum states in low-dimensional electron systems, dramatically influencing their thermodynamic properties and charge-transport behaviour. Study of such electron localisation induced by an aperiodic
lattice potential remains exceptionally challenging in solid-state systems, since extrinsic disorders can trivially trap electrons in potential minima near disorders, obscuring the underlying
quantum-mechanical origin of localisation phenomena. Van der Waals
heterostructures can provide an alternative route for explorations of the phenomena via the emergence of superlattice potentials generated by rotating and stacking individual layers. Here, we report strong signatures of electron localisation in helical trilayer
graphene, where the interplay of two moiré patterns gives rise to a moiré-of-moiré superlattice with distinct regions of moiré-periodic and moiré-aperiodic potentials. Remarkably, our measurements reveal the presence of double moiré-induced bands and high-order Brown-Zak oscillations, which are direct reflections of the periodic region with two constituent moiré patterns, and a superimposed anomalous hysteretic signal attributable to the aperiodic region. The data strongly suggest that electron wave functions are partially localised driven by the loss of a periodic
lattice potential. Our work provides insight into the effects of spatially inhomogeneous
lattice potentials on the low-dimensional electronic states and introduces a promising approach to control electron localisation for practical applications in solid-state devices.
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All authors Hangyeol Park, Junhyeok Oh, Rasoul Ghadimi, Chiranjit Mondal, Yungi Jeong, Won Beom Choi, Kenji Watanabe, Takashi Taniguchi, Bohm-Jung Yang, Joonho Jang
Mesoscale and Nanoscale Physics · Cross-listed from physics.optics
Optical spin precession
Abanoub Mikhail, Maxim Mazanov, Ilya Deiry et al. (+3 more)
Period-averaged electromagnetic
spin angular momentum is a well-established quantity for monochromatic fields, governing phenomena such as light-matter interactions with
chiral particles and
spin-orbit coupling effects. In contrast, the
spin angular momentum of non-monochromatic fields remains unexplored. Here, we extend the concept of optical
spin to the domain of non-monochromatic electromagnetic fields. Through this formulation, we uncover the precessional dynamics of electromagnetic
spin in specific polychromatic configurations, including the superposition of circularly and linearly polarized plane waves propagating orthogonally at different frequencies, as well as fields generated by a precessing
magnetic dipole. We discover that the dynamics of the electromagnetic
spin in these cases obeys a Landau-Lifshitz-like equation establishing a profound parallel between dynamics of magnetization and photonic
spin.
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All authors Abanoub Mikhail, Maxim Mazanov, Ilya Deiry, Mingzhao Song, Ivan Iorsh, Andrey Bogdanov
Quantum Gases · Cross-listed from quant-ph
Adiabatic pumping of topological corner states by coherent tunneling in a 2D SSH model
Yang Peng, Rui-Shan Li, Yan-Jue Lv et al. (+1 more)
The active manipulation of topologically protected states represents a pivotal frontier for
quantum technologies, offering a unique confluence of topological robustness and precise
quantum control. We propose an adiabatic pumping scheme for the long-range transfer of topological corner states in a two-dimensional Su-Schrieffer-Heeger model. The protocol utilizes a modular
lattice architecture composed of four topologically distinct subblocks, enabling the modulation of a topological dark state by precise tuning of
lattice couplings. This approach is based on coherent tunneling by adiabatic passage among topological corner and interface states. We establish a multi-level model for the adiabatic pumping that provides an accurate description of the underlying mechanism. In comparison with a sequential two-stage Thouless pumping, our protocol offers superior performance in both transfer fidelity and efficiency.
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All authors Yang Peng, Rui-Shan Li, Yan-Jue Lv, Yi Zheng
Statistical Mechanics
Entropy production and non-Gaussianity of fast processes at weak damping
Mario A. Ciampini, Jakob Rieser, Nikolai Kiesel et al. (+1 more)
We present a method of estimating the rate of
entropy production in underdamped dynamics by decomposing it into contributions originating in different non-
equilibrium effects. Specifically, a non-zero average velocity, a non-thermal width of the velocity distribution, correlations between position and velocity and non-Gaussian velocity statistics represent different ways in which the system can be out of
equilibrium and each give rise to a positive contribution to the overall
entropy production rate. We demonstrate that each contribution can be separately estimated from experimental trajectory data of levitated nano-particles subject to non-linear forces. We find that the majority of the
entropy production rate can be attributed to the first three contributions which can be estimated from the first and second moments of the position and velocity and therefore result in a useful \enquote{Gaussian} estimate for the
entropy production rate.
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All authors Mario A. Ciampini, Jakob Rieser, Nikolai Kiesel, Andreas Dechant
Strongly Correlated Electrons
Emergent Fermi-liquid-like phase by melting a holon Wigner crystal in a doped Mott insulator on the kagome lattice
Xu-Yan Jia, Wen Huang, D. N. Sheng et al. (+1 more)
The doped
quantum spin liquid on the kagome
lattice provides a fascinating platform to explore exotic
quantum states, such as the reported holon Wigner
crystal at low doping. By extending the doping range to $\delta = 0.027$ - $0.36$, we study the kagome-
lattice $t$-$J$ model using the state-of-the-art density
matrix renormalization group calculation. On the $L_y=3$ cylinder ($L_y$ is the number of unit
cells along the circumference direction), we establish a
quantum phase diagram with increasing doping level. In addition to the charge density wave (CDW) states at lower doping, we find an emergent
Fermi-
liquid-like phase by melting the holon Wigner
crystal at $\delta \approx 0.15$, which is characterized by suppression of charge density oscillation and power-law decay of various correlation functions. On the wider $L_y = 4$ cylinder, the bond-dimension extrapolated correlation functions also support such a
Fermi-
liquid-like state, suggesting its stability with increasing system size. In a narrow doping range near $\delta = 1/3$ on the $L_y = 3$ cylinder, we find a state with an exponential decay of single-particle correlation but the other correlation functions preserving the features in the
Fermi-
liquid-like phase, which may be a precursor of a superconducting state. Nevertheless, this peculiar state near $\delta = 1/3$ disappears on the $L_y = 4$ cylinder, implying a possible
lattice size dependence. Our results reveal a
quantum melting from a holon Wigner
crystal to a
Fermi-
liquid-like state with increasing hole density, and suggest a doping regime to explore superconductivity for future study.
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All authors Xu-Yan Jia, Wen Huang, D. N. Sheng, Shou-Shu Gong
Mesoscale and Nanoscale Physics
Protected valley splitting against interface disorder toward scalable silicon electron spin qubits
Yang Liu, Gang Wang, Shan Guan et al. (+2 more)
Regardless of various material design strategies, experimentally achieving substantial and controllable valley splitting in Si/SiGe
quantum wells remains a central challenge for ensuring high gate uniformity. This difficulty arises from unavoidable atomic-scale disorder at the interface, caused by
alloy randomness, which suppresses valley splitting and, more critically, induces large variations. Here, we demonstrate that CMOS-compatible uniaxial strain can substantially enhance valley splitting, rendering it immune to interface disorder. Atomistic pseudopotential calculations show that uniaxial strain linearly restores the valley splitting suppressed by interfacial disorder, with a large enhancement rate, while keeping disorder-induced variations within a narrow distribution. We reveal that uniaxial strain introduces a new coupling channel between bulk valleys in adjacent Brillouin zones through a small momentum transfer, which markedly reduces the susceptibility of valley splitting to interfacial disorder. These findings establish a viable route to improve gate uniformity in silicon-based
spin qubits, paving the way for scalable
quantum processors.
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All authors Yang Liu, Gang Wang, Shan Guan, Jun-Wei Luo, Shu-Shen Li
Materials Science
Scalable Synthesis of Large-Area WS2 Thin Films from Tungsten Precursors by Thermal CVD and Their Application in Schottky-Barrier Solar Cells
Jisun Kim, Yoosuk Kim, Seung-Ho Park et al. (+2 more)
Two-dimensional tungsten disulfide (WS2) is a promising
semiconductor for next-generation optoelectronic and photovoltaic devices, but scalable routes to uniform, large-area films remain challenging. In this study, a systematic thermal chemical vapor deposition (T-CVD) strategy is presented to synthesize centimeter-scale WS2 thin films by sulfurizing tungsten (W) precursors in a controlled sulfur vapor environment. High-purity sputtered W thin films on SiO2/Si and W foils were sulfurized at temperatures between 400 and 1000 C, with Raman spectroscopy identifying 800 C as the optimal growth temperature. Under these conditions, the films exhibit the characteristic E12g (349.7 cm-1) and A1g (416.8 cm-1) modes with narrow full-width at half-maximum values, indicative of high crystallinity and controlled thickness. Optical microscopy, scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy collectively validate the creation of stoichiometric, layered WS2 with significantly enhanced uniformity and diminished roughness when utilizing sputtered W thin films in contrast to W foils. Leveraging this optimized process, WS2 films grown on W foils were transferred onto target substrates, including indium tin
oxide (ITO)-coated glass, using a PMMA-assisted wet-transfer method that preserves structural integrity over large areas. Schottky-barrier
solar cells with an Au/WS2/ITO architecture fabricated from these films deliver a short-
circuit current density of 7.91 mA cm-2, an open-
circuit voltage of 0.495 V, and a power conversion efficiency of 1.45 percent. These results demonstrate that sulfurization of W thin films and foils via T-CVD provides a scalable, substrate-compatible platform for integrating WS2 into practical optoelectronic and low-cost photovoltaic technologies.
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All authors Jisun Kim, Yoosuk Kim, Seung-Ho Park, Yong Hun Ko, Chong-Yun Park
Materials Science
Collective Magnetic Excitations in a Photo-excited Electron-doped Cuprate Superconductor
Daniel Jost, Jiarui Li, Jordyn Hales et al. (+21 more)
Elucidating the microscopic behavior of cuprates under ultrafast photoexcitation offers critical insights into their highly correlated out-of-
equilibrium states. Although quasiparticle dynamics have been investigated extensively, the behavior of collective
magnetic excitations remains comparatively unexplored. Here, we use time-resolved resonant inelastic X-ray scattering (trRIXS) at the Cu $L_3$-edge to track the collective
magnetic excitations (paramagnons) in an optimally electron-doped cuprate driven out-of-
equilibrium by a femtosecond pump
laser pulse. Upon pumping, we observed an anti-Stokes signal associated with paramagnon generation, which modifies the paramagnon dispersion near the zone center, although the bandwidth remained unchanged. Moreover, the spectral weight exhibits a momentum-dependent variation across the Brillouin zone. The light-driven boost of the paramagnon population and the resulting spectral-weight transfer could provide new leverage to manipulate the properties of cuprates.
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All authors Daniel Jost, Jiarui Li, Jordyn Hales, Jonathan Sobota, Giacomo Merzoni, Leonardo Martinelli, Shuhan Ding, Kejun Xu, Justine Schlappa, Andreas Scherz, Robert Carley, Benjamin E. Van Kuiken, Teguh C. Asmara, Le Phuong Hoang, Laurent Mercadier, Sergii Parchenko, Martin Teichmann, Patrick S. Kirchmann, Giacomo Ghiringhelli, Brian Moritz, Zhi-Xun Shen, Thomas P. Devereaux, Yao Wang, Wei-Sheng Lee
Materials Science
Electric Current Control of Helimagnetic Chirality from a Multidomain State in the Helimagnet MnAu$_2$
Yuta Kimoto, Hidetoshi Masuda, Jun-ichiro Ohe et al. (+3 more)
In this paper, we study the domain wall dynamics under electric current in the helimagnet MnAu$_2$. We have found that the threshold electric current of the transition from a multidomain state to a single-
chiral domain state in a
magnetic field is much lower than that of chirality reversal from a single-
chiral domain within certain ranges of temperature and
magnetic field. The chirality after the transition depends on whether the
magnetic field and electric current were parallel or antiparallel. Numerical calculations based on the Landau-Lifshitz-Gilbert equation reproduced the experimental observations. These results indicate that the domain walls are highly mobile in the helimagnet.
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All authors Yuta Kimoto, Hidetoshi Masuda, Jun-ichiro Ohe, Shoya Sakamoto, Takeshi Seki, Yoshinori Onose
Superconductivity
Evidence for Anion-Free-Electron Duality and Enhanced Superconducting Role of Interstitial Anionic Electrons in Electrides
Zhao Liu, Xiang Wang, Yin Yang et al. (+10 more)
The discovery of superconducting electrides, characterized by interstitial anionic electrons (IAEs) residing in
lattice cavities, has established a distinctive platform for investigating
superconductors. Yet the superconducting origin and the fundamental role of IAEs in Cooper pairing formation remain poorly understood due to the challenges in directly observing IAEs. Here, combining angle-resolved photoemission spectroscopy (ARPES), transport measurements, and first-principles calculations, we certify that the IAEs in electride La3In (Tc = 9.4 K) exhibit a dual nature as both anions and free electrons. With the finite-depth potential well model, we trace that IAEs originate from electronic states near the
Fermi level located above potential barriers, forming a
Fermi sea susceptible to scattering by La-derived
phonons, triggering superconductivity. ARPES combined with high-resolution XRD measurements on oxygen-treated samples directly reveals IAEs' spatial distribution and energy dispersion from interstitial sites with the consistent energy value predicted by our theory model. The concomitant diminution of free electrons upon oxygen treatment, leading to a marked reduction in superconductivity, further provides compelling experimental evidence that IAEs actively participate in electron-
phonon coupling. Our findings resolve the long-standing ambiguity regarding the electronic nature of IAEs, elucidate their enhancing superconductivity in the
phonon-mediated mechanism, and provide a foundation for exploring advanced electride-based
superconductors.
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All authors Zhao Liu, Xiang Wang, Yin Yang, Pengcheng Ma, Zhijun Tu, Xinyu Wang, Donghan Jia, Wenju Zhou, Huiyang Gou, Hechang Lei, Qiang Xu, Zhonghao Liu, Tian Cui
Superconductivity
A chemical avenue to manipulate field-reentrant superconducting rivalries in infinite layer nickelates
Haowen Han, Yusong Zhao, Yi Bian et al. (+14 more)
Recently, preliminary
magnetic field-reentrant superconductivity manifested in high-temperature (Tc) Eu-doped infinite-layer (IL) nickelates, beyond analogous discoveries exclusively in low-Tc systems. This evokes intriguing fundamental issues about potential
quantum-phase boundary and criticality between unconventional superconductivity and field-reentrant-one, which are inexplicable owing to formidable challenges in growing IL-nickelates towards later-series rare-earths. Herein, we open up chemical avenues to enable effective growth of (RE1-yRE'y)1-xEuxNiO2 (RE/RE': Pr, Nd, Sm, Gd, Dy), giving rise to discoveries of RE-4f-related
quantum competition between high-Tc and reentrant superconductivity. Robust
magnetic-field-reentrant superconductivity with uniaxial anisotropy is observed at superconducting-dome boundaries, stemming from Eu2+-4f7 associated competition between
magnetic-fluctuation promoted pairing and exchange-field interactions. Their
quantum-criticality is further modulable via RE(RE')-magnetism, which either reinforces reentrancy or elevates Tc (40.1 K) with more robust critical-current-density (~266 kA/cm2 at 2 K) beyond Sr-/Ca-doped counterparts. Our synthetic route enables the establishment of an ideal platform via IL-nickelates for studying 4f-related unconventional superconductivity and
quantum-criticality.
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All authors Haowen Han, Yusong Zhao, Yi Bian, Tong Ma, Wenlong Yang, Shaohua Yang, Binghui Ge, Hongliang Dong, Chuanying Xi, Ze Wang, Nuofu Chen, Tian Shang, Toni Shiroka, Zaher Salman, Jia-Cai Nie, Ho-Kwang Mao, Jikun Chen
Statistical Mechanics
Shaping causality: programmable nonlocal signal generation in long-range spin systems
Shreyas Sadugol, Giuseppe Luca Celardo, Fausto Borgonovi et al. (+1 more)
Understanding how information spreads in non-relativistic many-body systems is a central issue for
quantum information processing. While short-range interactions confine information within a local light cone, long-range interactions typically lead to uncontrolled nonlocal spread across the entire system. Here, we demonstrate that this apparent dichotomy is not fundamental and that nonlocality in systems with long-range interactions can be deterministically controlled. By mapping
spin dynamics to a hard-core
boson chain, we identify a regime in which the causal space-time landscape can be precisely shaped. We show that placing
spin excitations in a polarized background allows a local perturbation to trigger nonlocal signals exactly at the positions of these excitations. These pre-selected sites act as seeds for new, effective light cones, allowing information to bypass the bulk and re-emerge at distant, programmable locations. This mechanism avoids uncontrollable global nonlocality while circumventing the speed limits associated with local transport. By engineering these nonlocal communication channels, our findings offer a versatile framework for information distribution relevant to
quantum memories, error correction, and programmable platforms such as trapped ions.
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All authors Shreyas Sadugol, Giuseppe Luca Celardo, Fausto Borgonovi, Lev Kaplan
Disordered Systems and Neural Networks
Evolving disorder in non-Hermitian lattices
I. Komis, E. T. Kokkinakis, K. G. Makris et al. (+1 more)
The impact of disorder on wave transport has been extensively studied in Hermitian systems, where static randomness gives rise to Anderson localization. In non-Hermitian
lattices, static disorder can lead to peculiar transport features, including jumpy wave
evolution. By contrast, much less is known about how transport is modified when the on-site disorder evolves during propagation. Here we address this problem by investigating two pertinent non-Hermitian
lattice models with disorder altered at regular intervals, characterized by a finite disorder period. In
lattices with symmetric couplings and complex on-site disorder, short disorder periods suppress localization and give rise to
diffusion-like spreading, while longer periods allow the emergence of jumps. In Hatano-Nelson
lattices with real on-site disorder, the non-Hermitian skin effect asymptotically dominates regardless of the disorder strength, while the disorder period reshapes the drift velocity and modulates its competition with Anderson localization. These results establish evolving disorder as a novel way of tuning non-Hermitian transport.
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All authors I. Komis, E. T. Kokkinakis, K. G. Makris, E. N. Economou
Soft Condensed Matter · Cross-listed from physics.flu-dyn
Droplet mobilization in actuated deformable tubes
Sthavishtha R. Bhopalam, Ruben Juanes and Hector Gomez
We study the mobilization of an oil droplet in a deformable, actuated constricted tube subjected to two different actuation mechanisms: hydrodynamic actuation (oscillatory body force in the fluid) and dynamic wall actuation (oscillatory traction on the tube walls). Using high-resolution fluid-structure interaction simulations, we analyze the effects of actuation frequency and amplitude on droplet transport through the constriction. Our simulations show that hydrodynamic actuation leads to a monotonic increase in the droplet's mobilization time with increasing actuation frequency, and a decrease with increasing actuation amplitude. In contrast, dynamic wall actuation exhibits a resonance effect-the mobilization time reaches a minimum at a frequency near the tube's resonant frequency. Our study highlights the potential of actuation mechanisms in deformable tubes for precise control of droplet transport in bio-microfluidic applications.
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Strongly Correlated Electrons
Pervasive electronic nematicity as the parent state of kagome superconductors
Muxian Xu, Siyu Cheng, Andrea Capa Salinas et al. (+10 more)
Kagome
superconductors $A$V$_3$Sb$_5$ ($A$ = Cs, K, Rb) have developed into an exciting playground for realizing and exploring exotic solid state phenomena. Abundant experimental evidence suggests that electronic structure breaks rotational
symmetry of the
lattice, but whether this may be a simple consequence of the
symmetry of the underlying 2 $\times$ 2 charge density wave phase or an entirely different mechanism remains intensely debated. We use spectroscopic imaging scanning tunneling microscopy to explore the phase diagram of the prototypical kagome
superconductor CsV$_3$Sb$_5$ as a function of doping. We intentionally suppress the charge density wave phase with chemical substitutions selectively introduced at two distinct
lattice sites, and investigate the resulting system. We discover that rotational
symmetry breaking of the electronic structure – now present in short-range nanoscale regions – persists in all samples, in a wide doping range long after all charge density waves have been suppressed. As such, our experiments uncover ubiquitous electronic nematicity across the $A$V$_3$Sb$_5$ phase diagram, unrelated to the 2 $\times$ 2 charge density wave. This further points towards electronic nematicity as the intrinsic nature of the parent state of kagome
superconductors, under which other exotic low-temperature phenomena subsequently emerge.
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All authors Muxian Xu, Siyu Cheng, Andrea Capa Salinas, Ganesh Pokharel, Alexander LaFleur, Hong Li, Hengxin Tan, Brenden R. Ortiz, Qinwen Deng, Binghai Yan, Ziqiang Wang, Stephen D. Wilson, Ilija Zeljkovic