Materials Science
Light-Induced Even-Parity Unidirectionally Polarized Spin Splitting in Coplanar Antiferromagnets
Di Zhu, Dongling Liu, Zheng-Yang Zhuang et al. (+2 more)
When a coplanar antiferromagnet (AFM) with $xy$-plane
magnetic moments exhibits a
spin-split band structure and unidirectional
spin polarization along $z$, the
spin polarization is forced to be an odd function of momentum by the fundamental
symmetry $[\bar{C}_{2z}\|\mathcal{T}]$. Coplanar AFMs displaying such odd-parity, unidirectionally polarized
spin splittings are known as odd-parity magnets. In this work, we propose the realization of their missing even-parity counterparts. We begin by deriving the
symmetry conditions required for an even-parity, out-of-plane
spin splitting. We then show that irradiating a
spin-degenerate coplanar AFM with circularly polarized light lifts the $[\bar{C}_{2z}\|\mathcal{T}]$ constraint, dynamically generating this even-parity state. Specifically, the light-induced unidirectionally polarized
spin splitting exhibits a $d$-wave texture in momentum space, akin to that of a $d$-wave altermagnet. We prove this texture's robustness against
spin canting and propose time-,
spin- and angle-resolved photoemission photocurrent as a direct probe. Our work demonstrates that optical driving can generate novel
spin-split phases in coplanar AFMs, thereby diversifying the landscape of materials exhibiting distinct
spin splittings.
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All authors Di Zhu, Dongling Liu, Zheng-Yang Zhuang, Zhigang Wu, Zhongbo Yan
Materials Science
Peridynamic modeling of the crack velocity dependence via an incubation time fracture criterion
M. Ignatev, P. Weißgraeber, E. Oterkus et al. (+1 more)
This study investigates one of the central problems of dynamic fracture mechanics, namely the dependence of the instantaneous stress intensity factor (SIF) on the crack propagation velocity. For this purpose, the well-known experiments by Ravi-Chandar and Knauss on brittle, amorphous Homalite-100
polymer plates are modeled using a peridynamic approach. The numerical model integrates the previously proposed remote stress fracture criterion into an incubation time fracture criterion. Results of numerical modeling indicate a significant variation in SIF values at an almost constant crack propagation velocity. Moreover, for higher crack propagation velocities, micro-branching is obtained numerically, leading to a larger scatter of SIF values. These effects were also observed in the experiments of Ravi-Chandar and Knauss, which provides new insights into the nature of the crack-velocity dependence of the Mode-I SIF.
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All authors M. Ignatev, P. Weißgraeber, E. Oterkus, L. Radtke
Materials Science
Fine and Hyperfine Interactions with Multi-level Spin Relaxation of the purified Giese-Salt in Veterinary Medicine: Prussian Blue Compound Ammonium-Ferric-Hexacyano-Ferrate
Sascha Albert Bräuninger, Damian Alexander Motz, Sebastian Praetz et al. (+6 more)
Ammonium ferric hexacyanoferrate is a veterinary-medical milestone and antidote against radiocesium, well-known as Giese-salt after the Chernobyl disaster fed to domestic and wild animals, which shows even a rich interplay of properties in nanostructural chemistry and ferromagnetism. Among the broad analytical techniques, the ambivalence of macroscopic micrometer-sized agglomerates and nanoparticle sizes, a suggested enlarged Fe(II)$-$C$\equiv$N$-$Fe(III) bond length by Fe K-edge XAFS results and multi-level
spin relaxation in $^{57}$Fe Mössbauer spectroscopy are highlighted. This sets this underestimated compound in a new light, e.g., for modern biomedicine and biofunctionality, extending its essential importance in addition to hypothetical future
nuclear incidents
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All authors Sascha Albert Bräuninger, Damian Alexander Motz, Sebastian Praetz, Felix Seewald, Katharina Strecker, Carla Vogt, Hans-Henning Klauss, Birgit Kanngießer, Hermann Seifert
Materials Science · Cross-listed from cond-mat.mes-hall
Emulating 2D Materials with Magnons
Bobby Kaman, Jinho Lim, Yingkai Liu et al. (+1 more)
Spin waves (
magnons) in 2D materials have received increasing interest due to their unique states and potential for tunability. However, many interesting features of these systems, including Dirac points and topological states, occur at high frequencies, where experimental probes are limited. Here, we study a
crystal formed by patterning a hexagonal array of holes in a perpendicularly magnetized thin film. Through simulation, we find that the magnonic band structure imitates that of
graphene, but additionally has some kagome-like character and includes a few flat bands. Surprisingly, its nature can be understood using a 9-band tight-binding
Hamiltonian. This clear analogy to 2D materials enables band-gap engineering in 2D, topological
magnons along 1D phase boundaries, and spectrally isolated modes at 0D point defects. Interestingly, the 1D phase boundaries allow access to the valley degree of freedom through a magnonic analog of the
quantum valley-
Hall insulator. These approaches can be extended to other magnonic systems, but are potentially more general due to the simplicity of the model, which resembles existing results from electron,
phonon,
photon, and cold atom systems. This finding brings the physics of
spin waves in 2D materials to more experimentally accessible scales, augments it, and outlines a few principles for controlling magnonic states.
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All authors Bobby Kaman, Jinho Lim, Yingkai Liu, Axel Hoffmann
Materials Science
Kinetic Flux Equations for Ion Exchange in Silicate Glasses
Guglielmo Macrelli
Ion exchange kinetic flux equations have been extensively investigated since the mid-twentieth century and continue to provide a fundamental framework for describing mass transport phenomena in solid materials. Despite the maturity of this field, inconsistencies remain in the literature concerning the definition, dimensional consistency, and physical interpretation of the parameters involved. A rigorous and unified treatment of these equations is therefore essential to ensure the reproducibility and comparability of theoretical and experimental studies. The present study aims to establish a coherent and systematic development of ion exchange kinetic flux equations, with particular emphasis on the consistent definition and dimensional formulation of the relevant physical quantities. Beyond refining the theoretical foundations, this study extends the classical formulation by incorporating the influence of mechanical stress on ion transport and considering cross-term interactions within the framework of linear irreversible thermodynamics. This study investigates ion-exchange kinetics within silicate glasses, operating under the Nernst-Planck binary interdiffusion regime. These developments provide a more comprehensive description of ion exchange kinetics, particularly as applied to silicate glasses, where coupling between chemical and mechanical effects plays a crucial role in determining transport behavior and performance.
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Materials Science
Interface-induced band bending and charge separation in all-organic ZnPc/F$_x$ZnPc heterostructures
Stephanie Amos, Neno Fuller, Wai-Lun Chan et al. (+1 more)
Organic
semiconductors are attractive building blocks for electronic devices due to their low cost and flexibility. Furthermore,
heterostructures with type-II band
alignments can efficiently separate photogenerated charges via a charge transfer and separation process. Here, we use density functional theory (DFT) to investigate model interfaces formed by zinc phthalocyanine (ZnPc) and its fluorinated derivatives (F$_8$ZnPc and F$_{16}$ZnPc). We demonstrate that these interfaces not only exhibit a type-II band offset, but also band bending. The band bending causes both the LUMO and HOMO states to localize away from the interface. Therefore, the band bending creates a strong driving force for charge separation. We used ultraviolet photoemission spectroscopy (UPS) to experimentally confirm this predicted band bending. The wavefunction envelopes of vertically-stacked molecules resemble particle-in-a-box states, but this shape is lost when the molecules are staggered. These results elucidate how interface-induced band bending facilitates charge separation in all-organic
heterostructures and suggest a design pathway toward improved performance in organic photovoltaic devices.
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All authors Stephanie Amos, Neno Fuller, Wai-Lun Chan, Hartwin Peelaers
Materials Science
Novel fast Li-ion conductors for solid-state electrolytes from first-principles
Tushar Singh Thakur, Loris Ercole and Nicola Marzari
We present a high-throughput computational screening for fast lithium-ion conductors to identify promising materials for application in all solid-state electrolytes. Starting from more than 30,000 Li-containing experimental structures sourced from Crystallography Open Database, Inorganic
Crystal Structure Database and Materials Platform for Data Science, we perform highly automated calculations to identify electronic
insulators. On these ~1000 structures, we use molecular dynamics simulations to estimate Li-ion diffusivities using the pinball model, which describes the potential energy landscape of diffusing lithium with accuracy similar to density functional theory while being 200-500 times faster. Then we study the ~60 most promising and previously unknown fast conductors with full first-principles molecular dynamics simulations at several temperatures to estimate their activation barriers. The results are discussed in detail for the 9 fastest conductors, including $Li_7NbO_6$ which shows a remarkable ionic conductivity of ~5 mS/cm at room temperature. We further present the entire screening protocol, including the workflows where the accuracy of the pinball model is improved self-consistently, necessary to automatically running the required calculations and analysing their results.
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Materials Science · Cross-listed from cond-mat.mes-hall
Thermal conductance across bonded SiOx-SiOx interfaces in hybrid bonding process
Xingqiang Zhang, Liu Chang, Liyi Li et al. (+1 more)
Hybrid bonding is a pivotal technology for enabling three dimensional integrated
circuits. Among the foremost challenges facing 3D IC implementation is thermal management, where a deep understanding of heat conduction across bonded interfaces is essential for addressing heat dissipation and reliability issues. Nevertheless, the thermal conductance of bonded dielectric-dielectric interfaces remains poorly understood. In this study, we employ the low-temperature bonding technique integral to hybrid bonding to fabricate SiO-SiO interfaces and investigate their thermal boundary conductance using time domain thermoreflectance. Structural characterizations show high quality bonded interfaces. By fitting the data with an equivalent multilayer thermal model, we establish a lower limit TBC of 150 MW/m2-K for the SiO-SiO interfaces, which corresponds to a thermal resistance lower than that of a 9.2-nm-thick dielectric layer. These findings offer valuable insights into thermal transport in hybrid-bonded structures and provide critical guidance for the thermal design of advanced packaging solutions.
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All authors Xingqiang Zhang, Liu Chang, Liyi Li, Zhe Cheng
Materials Science
Charge Transport in Thin-Film Transistors Based on Liquid-Crystalline Phthalocyanines
L. B. Avila, Zuchong Yang, Ilknur Hatice Eryilmaz et al. (+6 more)
We investigate a series of
liquid-crystalline phthalocyanines (metal-free and Cu, Zn, Ni, Co complexes) by correlating their vibrational signatures with their electronic performance in organic thin-film transistors (OTFTs). Raman spectroscopy reveals metal-dependent distortions of the phthalocyanine macrocycle, reflected in systematic shifts of the C-N-C and M-N vibrational modes. When integrated into OTFTs, all compounds exhibit markedly enhanced current response under ultrahigh
vacuum compared to an N2-rich environment, demonstrating that intrinsic charge transport is strongly suppressed by atmospheric species. Temperature-dependent measurements (100-300 K) show clear threshold-voltage shifts driven by deep interface and bulk traps, while all devices display thermally activated mobility with low activation energies (14-20 meV). These results highlight how mesomorphic order, metal coordination, and environmental conditions collectively govern charge transport in
liquid-crystalline phthalocyanines, offering design guidelines for their use as orientable semiconducting materials in organic electronics.
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All authors L. B. Avila, Zuchong Yang, Ilknur Hatice Eryilmaz, Lilian Skokan, Leonardo N Furini, Andreas Ruediger, H. Bock, I.H. Bechtold, E. Orgiu
Materials Science · Cross-listed from cond-mat.mes-hall
Signatures of moiré intralayer biexcitons and exciton-phason coupling in WSe2/WS2 heterostructures
Ranju Dalal, Harsimran Singh, Rwik Dutta et al. (+6 more)
Interactions among electronic and
lattice degrees-of-freedom are foundational to various phases in condensed-matter physics, yet the dynamic interplay between excitonic and phononic quasiparticles represents an equivalent, underexplored frontier. Moiré superlattices provide an ideal platform for realizing these interactions by offering localized intralayer
excitons (IALX) and ultralow-energy collective
lattice modes, such as phasons. Here, by optically suppressing ultrafast charge-transfer (CT) to interlayer
excitons in WSe2/WS2
heterostructures, we uncover dynamics of moiré IALX revealing long lifetimes ({\tau} > 1000 ps) arising from localized Wannier and in-plane CT nature. We then observe moiré intralayer intervalley biexcitons with binding energy ~ 16 meV, with long lifetimes due to moiré confinement. Furthermore, we find time-domain signatures of strong coupling between moiré-IALX and ~ 10 micro-eV phasons, evidenced as twist-angle-dependent GHz oscillations in IALX dynamics. Our findings establish moiré superlattices as interacting hybrid
quantum systems and for engineering non-
equilibrium phenomena, as well as for GHz-scale optoelectronics.
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All authors Ranju Dalal, Harsimran Singh, Rwik Dutta, Hariharan Swaminathan, Kenji Watanabe, Takashi Taniguchi, Mit H Naik, Manish Jain, Akshay Singh
Materials Science · Cross-listed from cond-mat.mes-hall
Shubnikov-de Haas oscillations of two-dimensional electron gases in AlYN/GaN and AlScN/GaN heterostructures
Yu-Hsin Chen, Thai-Son Nguyen, Isabel Streicher et al. (+4 more)
AlYN and AlScN have recently emerged as promising nitride materials that can be integrated with GaN to form two-dimensional electron gases (2DEGs) at heterojunctions. Electron transport properties in these
heterostructures have been enhanced through careful design and optimization of epitaxial growth conditions. In this work, we report for the first time Shubnikov-de Haas (SdH) oscillations of 2DEGs in AlYN/GaN and AlScN/GaN
heterostructures, grown by metal-organic chemical vapor deposition. SdH oscillations provide direct access to key 2DEG parameters at the
Fermi level: (1) carrier density, (2) electron effective mass (m* ~ 0.24 me for AlYN/GaN and m* ~ 0.25 me for AlScN/GaN), and (3)
quantum scattering time (~ 68 fs for AlYN/GaN and ~ 70 fs for AlScN/GaN). These measurements of fundamental transport properties provide critical insights for advancing emerging nitride
semiconductors for future high-frequency and power electronics.
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All authors Yu-Hsin Chen, Thai-Son Nguyen, Isabel Streicher, Jimy Encomendero, Stefano Leone, Huili Grace Xing, Debdeep Jena
Materials Science
Multiscale Experimental Evidence of a Transitory State in the HDA-LDA Transition in Alumino-sodo-silicate Glasses
Antoine Cornet, Thierry Deschamps, Sylvie Le Floch et al. (+2 more)
The structural
evolution with temperature of pure silica (SiO2), sodium-silicate (5Na2O-95SiO2, 10Na2O-90SiO2 and 25Na2O-75SiO2) and albite (15Na2O-15Al2O3-75SiO2) glasses previously densified from hot compression is monitored with a combination of small and wide angle x-ray scattering. Transient scattering maxima in the length scales associated with both techniques indicate the presence of a transitory state, suggesting the classification of the initial and final states as distinct glass states in the context of polyamorphism. In all glasses, a transient intensity peak in the small angle scattering is observed, consistent with the nucleation of a new amorphous state. Based on a comparison with the phenomenology observed in supercooled and glassy water, we propose that this structural
evolution provide a strong evidence of the glass polyamorphism as the consequence of the existence of an underlying but thermodynamically defined
liquid-
liquid transition, independent on the polymerization degree of the system.
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All authors Antoine Cornet, Thierry Deschamps, Sylvie Le Floch, Dominique de Ligny, Christine Martinet
Materials Science
Many-electron systems with fractional electron number and spin: exact properties above and below the equilibrium total spin value
Yuli Goshen and Eli Kraisler
In this work, we analyze the fundamental question of what is the ensemble ground state of a general, finite, many-electron system at zero temperature, with a given, possibly fractional, electron number $N_{tot}$ and a given $z$-projection of the
spin, $M_{tot}$, distinguishing between low- and high-
spin cases. For the low-
spin case, the general form of the ensemble ground state has been rigorously derived in J. Phys. Chem. Lett. 15, 2337 (2024), finding the presence of an ambiguity in the ground state. Here we further discuss this ambiguity, and show that it can be removed via maximization of the
entropy. For the high-
spin case, we find that the form of the ensemble ground state strongly depends on the system in question. Furthermore, we prove three general properties which characterize the ensemble, and narrow the list of pure states it may consist of. We relate the frontier Kohn-Sham orbital energies to total energy differences, providing a generalization of the ionization potential
theorem to systems with arbitrary fractional $M_{tot}$. Furthermore, we derive expressions for new derivative discontinuities, which appear as jumps in the KS potentials when crossing a boundary in the $N_{\uparrow}$-$N_{\downarrow}$ plane. Our analytical results are supported by an extensive numerical analysis of the Atomic Spectra Database of the National Institute of Standards. The new exact conditions for many-electron systems derived in this work are instrumental for development of advanced approximations in density functional theory and other many-electron methods.
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Materials Science
DeepH-pack: A general-purpose neural network package for deep-learning electronic structure calculations
Yang Li, Yanzhen Wang, Boheng Zhao et al. (+15 more)
In computational physics and materials science, first-principles methods, particularly density functional theory, have become central tools for electronic structure prediction and materials design. Recently, rapid advances in artificial intelligence (AI) have begun to reshape the research landscape, giving rise to the emerging field of deep-learning electronic structure calculations. Despite numerous pioneering studies, the field remains in its early stages; existing software implementations are often fragmented, lacking unified frameworks and standardized interfaces required for broad community adoption. Here we present DeepH-pack, a comprehensive and unified software package that integrates first-principles calculations with deep learning. By incorporating fundamental physical principles into neural-network design, such as the nearsightedness principle and the equivariance principle, DeepH-pack achieves robust cross-scale and cross-material generalizability. This allows models trained on small-scale structures to generalize to large-scale and previously unseen materials. The toolkit preserves first-principles accuracy while accelerating electronic structure calculations by several orders of magnitude, establishing an efficient and intelligent computational paradigm for large-scale materials simulation, high-throughput materials database construction, and AI-driven materials discovery.
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All authors Yang Li, Yanzhen Wang, Boheng Zhao, Xiaoxun Gong, Yuxiang Wang, Zechen Tang, Zixu Wang, Zilong Yuan, Jialin Li, Minghui Sun, Zezhou Chen, Honggeng Tao, Baochun Wu, Yuhang Yu, He Li, Felipe H. da Jornada, Wenhui Duan, Yong Xu
Materials Science
Surface reconstruction-driven band folding and spin-orbit enhancement at the $\alpha$-antimonene/Au(111) interface
Thomas Pierron, José de Jesùs Villalobos Castro, Etienne Barre et al. (+9 more)
The electronic properties of the two-dimensional (2D) $\alpha$ phase of antimonene are unique, featuring unpinned Dirac cones that can be moved with strain. Here we investigate the structural and electronic properties of an epitaxial 2D $\alpha$-antimonene, grown on Au(111). Using angle-resolved photoemission spectroscopy and density-functional theory, we reveal a strong hybridization at the Sb/Au interface, which imprints a rectangular reconstruction in the Au states, producing a band folding and hybrid bands exhibiting trigonal pockets. Additionally, hybridization displaces part of the Au wavefunction in regions of large electrostatic potential gradient, thereby enhancing
spin-orbit splitting. Our work underscores that the pristine electronic properties of $\alpha$-antimonene may be deeply modified by its substrate, and even overwhelmed by the bands of the latter, and also shows that
spin-orbit interaction in a heavy metal (Au) can be substantially enhanced by a lighter element (Sb).
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All authors Thomas Pierron, José de Jesùs Villalobos Castro, Etienne Barre, Dan Wang, Stephane Pons, Dimitri Roditchev, Azzedine Bendounan, Valerie Guisset, Philippe David, Johann Coraux, Lorenzo Sponza, Sergio Vlaic
Materials Science
Strain Engineering of Intrinsic Anomalous Hall and Nernst Effects in Altermagnetic MnTe at Realistic Doping Levels
Weiwei Chen, Ziyu Zhou, Jie Meng et al. (+3 more)
Hexagonal MnTe has emerged as a prototypical g-wave altermagnet, hosting time-reversal
symmetry breaking in momentum space despite a vanishing net magnetization. While this
symmetry breaking theoretically allows for an intrinsic anomalous
Hall effect, experimentally observed signals have remained weak. In this work, we investigate the origin of this suppression and demonstrate a strategy to amplify anomalous transport responses within the experimentally accessible doping regime. Using a $\bm{k}\cdot\bm{p}$ effective model, we reveal that near the valence band maximum, which corresponds to the energy window relevant for typical hole doping ($\sim10^{19}cm^{-3}$), the intrinsic
Hall effect is suppressed due to a
symmetry-enforced cancellation of opposing Berry
curvature contributions. We propose that breaking the crystalline
symmetry via volume-conserving biaxial strain lifts this cancellation, resulting in a significant enhancement of the anomalous
Hall conductivity by orders of magnitude. This strain-induced
Fermi surface distortion also amplifies the anomalous Nernst effect. Furthermore, the analysis of the
spin texture confirms that these strain-enabled anomalous transport signatures emerge while preserving the zero net magnetization.
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All authors Weiwei Chen, Ziyu Zhou, Jie Meng, Weiyi Wang, Ye Yang, Zhongjun Li
Materials Science
Observation of spin-valley locked nodal lines in a quasi-2D altermagnet
Quanxin Hu, Xingkai Cheng, Qingchen Duan et al. (+19 more)
The interplay among
quantum degrees of freedom-
spin, orbital and momentum-has emerged as a fertile ground for realizing
magnetic quantum states with transformative potential for electronic and spintronic technologies. Prominent examples include
ferromagnetic Weyl semimetals and
antiferromagnetic axion insulators. Recently, altermagnets(AMs) have been identified as a distinct
spin-splitting class of collinear antiferromagnets(AFMs), characterized by
crystal symmetry that connects
magnetic sublattices in real space and enforces C-paired
spin-momentum locking in reciprocal space. These materials combine the advantages of nonrelativistic
spin-polarization akin to FMs and vanished net-magnetization as AFMs, making them highly promising for spintronic applications. Furthermore, they introduce nontrivial
spin-momentum locking
spin texture as an additional degree of freedom for realizing novel
quantum phases. In this work, we report the discovery of a new type of
spin-valley-locked nodal line phase in the layered AM Rb-intercalated V{_2}Te{_2}O. By combining high-resolution
spin and angle-resolved photoemission spectroscopy with first-principles calculations, we observe the coexistence of both spinless and spinful nodal lines near the
Fermi level. Remarkably, the spinful nodal lines exhibit uniform
spin polarization within each valley, while displaying opposite
spin polarizations across
symmetry-paired valleys-a unique feature we term
spin-valley-locked nodal lines, which is exclusive to AMs. Direct measurements of out-of-plane band dispersion using a side-cleaving technique reveal the two-dimensional nature of these nodal lines. Our findings not only unveil a previously unexplored topological phase in AMs where valley-locked
spin as an additional
quantum character but also establish RbV{_2}Te{_2}O as a promising platform for spintronics, valleytronics, and moire-engineered
quantum devices.
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All authors Quanxin Hu, Xingkai Cheng, Qingchen Duan, Yudong Hu, Bei Jiang, Yusen Xiao, Yaqi Li, Mojun Pan, Liwei Deng, Changchao Liu, Guanghan Cao, Zhengtai Liu, Mao Ye, Shan Qiao, Zhanfeng Liu, Zhe Sun, Anyuan Gao, Yaobo Huang, Ruidan Zhong, Junwei Liu, Baiqing Lv, Hong Ding
Materials Science
Finite Element Simulation of NMC Particle Fracture during Calendering: a Route to Optimize Electrode Microstructures
Pierrick Guichard, Benoit Mathieu and Eric Woillez
Beyond active material intrinsic properties, the electrode manufacturing process is a crucial step to reach high energy density and long-life of Li-ion batteries. In particular, very high pressures are applied to the electrode during the calendering step, that directly influence the microstructure and the electrochemical performances. This article reports the first calendering simulation of a NMC cathode using a finite element method (FEM), including the post-fracturation behaviour of the secondary NMC particles. Calibrated with nano-indentation experiments, the mechanical model provides stress-strain predictions fully consistent with experimental data. On assemblies up to 100 particles, simulations reveal three calendering regimes along compression: particle rearrangement, moderatepressure fracturing, and complete crushing. The model shows the strong sensitivity of the electrode microstructure to the calendering pressure level, and can thus be used as a guidance in the multi-criteria optimization of the manufacturing process.
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Materials Science
Hybrid Disclination Skin-topological Effects in Non-Hermitian Circuits
Boyuan Li, Zekun Huang, Wenao Wang et al. (+6 more)
The bulk-disclination correspondence (BDC) is a fundamental concept in Hermitian systems that has been widely applied to predict disclination states. Recently, disclination states have also been observed and experimentally verified in non-Hermitian systems with C6
lattice symmetry, where gain and loss are introduced to induce non-Hermiticity. In this Letter, we propose a non-Hermitian two-dimensional (2D) Su-Schrieffer-Heeger (SSH) disclination model with skin-topological (ST) disclination states, and calculate its biorthogonal Zak phase. Together with the real-space disclination index, we predict the emergence of disclination states in a C4-symmetric non-Hermitian
lattice and the corresponding fractional charge. We also generalize the
symmetry indicator within the biorthogonal framework to predict the anomalous filling near the disclination core. Experimentally, the model is implemented on a nonreciprocal
circuit platform, where we analyze the impedance
matrix characterized by complex eigenfrequencies and directly observe the ST disclination states. Our work further extends the bulk-disclination correspondence to the non-Hermitian realm.
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All authors Boyuan Li, Zekun Huang, Wenao Wang, Jiaxi Wang, Yu Chen, Shaojie Ma, Ce Shang, Tie Jun Cui, Shuo Liu
Materials Science
Anomalous Hall transport in Mn$_{3}$Sn$_{0.5}$X$_{0.5}$C (X = Ge and Zn)
Sunil Gangwar and C. S. Yadav
Mn-based antiperovskites that exhibit topological surface states show potential applications in spintronics, magnetoelectronics, and
quantum devices owing to the interplay between magnetism and
topology. In this family of compounds, Mn$3$SnC exhibits a concurrent
ferromagnetic and
antiferromagnetic ground state below $T \sim 285$ K, along with a Berry
curvature driven anomalous
Hall effect. Here, we report the anomalous
Hall effect in Ge- and Zn-doped Mn$3$SnC compounds, namely Mn$3$Sn${0.5}$Ge${0.5}$C (MSGC) and Mn$3$Sn${0.5}$Zn${0.5}$C (MSZC). MSGC undergoes a paramagnetic to concurrent
antiferromagnetic and
ferromagnetic transition at $T_C \sim 300$ K, whereas MSZC exhibits a paramagnetic to
ferromagnetic transition at $T_C \sim 240$ K, followed by a
ferromagnetic to ferrimagnetic transition at $T_N \sim 170$ K. The electronic transport in these compounds is governed by electron-
phonon and electron-
magnon scattering and shows anomalous
Hall resistivity $\rho^A_{xy}$. Our analysis indicates that the anomalous
Hall effect arises from contributions of skew scattering and intrinsic Berry
curvature mechanisms, with electron-
phonon and electron-
magnon scattering playing an important role in skew scattering at high temperatures. Ge and Zn doping in Mn$_3$SnC significantly enhances the anomalous
Hall conductivity.
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Materials Science · Cross-listed from cond-mat.str-el
Possible inverse magnetic melting effect in vdW-like Kondo lattice CeSn$_{0.75}$Sb$_2$
Hai Zeng, Yiwei Chen, Zhuo Wang et al. (+5 more)
Given the intimate connection between
magnetic orders and the interplay among multiple degrees of freedom in heavy-
fermion systems, controlling and understanding the associated inverse melting effect is crucial for unveiling novel condensed-matter states and their potential applications. Here, we report the growth of single crystalline quasi-two-dimensional van-der-Waals-like (vdW-like) Kondo
lattice CeSn$_{0.75}$Sb$_2$, and its physical properties by a combination of transport /
magnetic / thermodynamic measurements. We find that it hosts a fragile
antiferromagnetic (AFM) order and a cluster glass (CG) ground state, both of which are highly sensitive to external fields. Upon cooling under low in-plane
magnetic fields, the AFM phase evolves into a polarized paramagnetic phase, either directly or indirectly through the intermediate CG phase. This process constitutes a possible inverse
magnetic melting effect that restores the broken translational / rotational
symmetries. Our work provides a rare paradigm of inverse
magnetic melting effect in vdW-like heavy-
fermion materials, and enriches the physics in conventional Kondo-
lattice models.
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All authors Hai Zeng, Yiwei Chen, Zhuo Wang, Shuo Zou, Kangjian Luo, Yang Yuan, Meng Zhang, Yongkang Luo
Materials Science
Transformation Journey of Zr-based MOFs: Study on Mechanics and Hydrogen Storage under Doping Regulation
Yanhuai Ding, Dan Qian and Zhipeng Liu
This study delves into the transformation journey of Zr-based Metal-Organic Frameworks (MOFs), focusing on enhancing their mechanical properties and hydrogen storage capacities through doping regulation. MOFs, a versatile class of crystalline porous materials, have garnered significant
attention due to their unique properties and broad potential applications in gas storage, separation, catalysis, and sensing. Among them, Zr-based MOFs stand out for their exceptional stability and high surface area. This research systematically investigates six key Zr-based MOFs (UIO-66, UIO-67, UIO-68, MOF-801, MOF-802, and MOF-841) using multiscale computational methods, including molecular dynamics (MD) simulations, grand canonical Monte Carlo (GCMC) simulations, and density functional theory (DFT). The study explores the impact of metal ion substitution (Fe, Co, Ni, Cu, Zn) on the mechanical and hydrogen storage properties of these MOFs. Our findings reveal that metal ion substitution significantly influences the mechanical stability and hydrogen adsorption capacity of Zr-based MOFs, providing valuable insights for the design and optimization of high-performance MOF materials.
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Materials Science
Anisotropic Kinetics of Ion-Irradiation-Induced Phase Transition in Gallium Oxide
Taiqiao Liu, Tongtong Wang, Zeyuan Li et al. (+8 more)
Radiation-tolerant
semiconductors have traditionally been engineered by the principle of suppressing defect accumulation and amorphization, based on the assumption that radiation damage is inherently
stochastic. Here we show that, in monoclinic $\beta$-\ce{Ga2O3}, a promising ultrawide-bandgap
semiconductor, surface crystallographic orientation deterministically governs radiation tolerance through highly anisotropic kinetics of the $\beta$-to-$\gamma$ phase transition. Using machine-learning molecular dynamics coupled with a local configurational-
entropy descriptor, we quantitatively map anisotropic $\beta$-to-$\gamma$ transition kinetics, showing that the critical dose, transition-layer depth, and kinetic stability of the $\gamma$-phase are fundamentally governed by surface orientation. Under ion irradiation, non-channeling surfaces such as (100), (001), and (-201) undergo severe surface amorphization, whereas the strongly channeling (010) surface resists damage accumulation and promotes subsurface $\gamma$-phase nucleation. During thermal annealing recovery process, these initial states follow two distinct recovery pathways: the channeling (010) surface reverts directly from $\gamma$-to-$\beta$, whereas non-channeling surfaces follow a sequential amorphous-to-$\gamma$-to-$\beta$ transition pathway. This work establishes surface orientation as a fundamental design principle for achieving radiation tolerance through controlled polymorphic transitions, providing a universal framework for engineering functional materials capable of withstanding extreme irradiation environments.
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All authors Taiqiao Liu, Tongtong Wang, Zeyuan Li, E Zhou, Junlei Zhao, Jiaren Feng, Xiaoyu Fei, Yuzheng Guo, Flyura Djurabekova, Sheng Liu, Zhaofu Zhang
Materials Science
Efficient Screening of Organic Singlet Fission Molecules Using Graph Neural Networks
Li Fu, Longfei Lv, Fan Zhang et al. (+3 more)
Singlet fission (SF) provides a promising strategy for surpassing the Shockley-Queisser limit in photovoltaics. However, the identification of efficient SF materials is hindered by the limited availability of suitable molecular candidates and the high computational costs associated with conventional
quantum-chemical methods for excited states. In this study, we introduce a high-throughput screening framework that integrates a graph neural network (GNN) with multi-level validation to accelerate the discovery of SF-active molecules. Trained on a previously reported FORMED database, the GNN achieves state-of-the-art accuracy in predicting SF-relevant excited-state properties, demonstrating a mean absolute error of about 0.1 eV for S1, T1, and T2 excitation energies. This capability facilitates the efficient screening of over 20 million molecular structures from both OE62 and QO2Mol databases. Our framework significantly reduces the computational demand associated with Time-Dependent Density Functional Theory validation by four orders of magnitude and identifies 180 potential SF molecules along with more than 1000 conformers. Subsequent assessments regarding synthetic accessibility, GW approximation and Bethe-Salpeter equation calculations further highlight a subset of experimentally feasible candidates among these SF candidates. The approach presented herein exemplifies an effective strategy for accelerating the discovery of functional molecules with optoelectronic applications.
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All authors Li Fu, Longfei Lv, Fan Zhang, Si Zhou, Weiwei Gao, Jijun Zhao
Materials Science · Cross-listed from cond-mat.stat-mech
Thermalized buckling of extensible, semiflexible polymers
Richard Huang, David R. Nelson and Suraj Shankar
The Euler buckling of rods is a long-studied mechanical instability, and it remains relevant to this day, as the constituent components in many biological and physical systems are linear
polymers, such as microtubules or carbon nanotubes. At finite temperature, if a
polymer is shorter than its persistence length, the
polymer is semiflexible, and its elasticity remains rod-like. But
polymers can also stretch due to their finite extensibility, which can couple to energetically cheap bending deformations in nonlinear ways when a load is applied to the system. We show how the interplay between thermal fluctuations and nonlinear elasticity dramatically modifies the Euler buckling instability for compressed semiflexible
polymers in a fixed strain ensemble. We identify a Ginzburg-like length scale beyond which thermally excited undulations lead to a softened Young's modulus, while the
polymer nevertheless remains semiflexible. Both perturbative calculations and numerical Monte Carlo simulations suggest a qualitative change in several scaling properties of the buckling transition. The critical compressional strain for thermal buckling now increases with system size, in contrast to athermal buckling, where it decreases with system size. Renormalization group calculations confirm this picture, and also show that thermal buckling is controlled by a new fixed point with different critical exponents compared to classical Euler buckling.
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Materials Science
Integrated magnonic chip using cascaded logic
Mengying Guo, Xudong Jing, Kristýna Davídková et al. (+10 more)
The transistor transformed not only electronics but everyday life, and the integrated
circuit - now simply the "chip" - made computation scalable and ubiquitous. Magnonics has long promised a parallel path to low-energy information processing by using
spin waves instead of charge. Progress, however, has been limited by two fundamental obstacles: intrinsic attenuation of
spin waves and the requirement for precisely normalised output intensity and input phase to ensure reliable logic operation - conditions that are difficult to maintain in large-scale
circuits owing to inevitable imperfections. Here, we report an integrated magnonic
circuit that overcomes both limitations through engineered nonlinearity in nanoscale yttrium iron garnet waveguides. Nonlinear self-adjustment of the
spin wave phase renders logic operation insensitive to the relative phases of the inputs, while a deeply nonlinear, threshold-activated self-normalised excitation restores and standardises the output intensity. Using space-resolved micro-focused Brillouin light scattering, we demonstrate reconfigurable AND, OR and three-input majority gates and realise deterministic cascading across sequential stages, establishing a scalable on-chip logic primitive. The architecture operates with gigahertz frequencies, supports dynamic threshold control for functional reconfiguration, and is compatible with scalable integration, making it attractive for adaptive and neuromorphic computing. By resolving phase-independent operation and signal restoration at the level of device physics, this work advances magnonics from isolated proof-of-concept devices towards integrated magnonic chips that can complement advanced CMOS in energy-constrained computing tasks.
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All authors Mengying Guo, Xudong Jing, Kristýna Davídková, Roman Verba, Zhenyu Zhou, Xueyu Guo, Carsten Dubs, Yiheng Rao, Kaiming Cai, Jing Li, Philipp Pirro, Andrii V. Chumak, Qi Wang
Materials Science · Cross-listed from physics.app-ph
Acoustic Analogy of Quantum Baldin Sum Rule for Optimal Causal Scattering
Sichao Qu, Zixiong Yu, Erqian Dong et al. (+2 more)
The mass law is a cornerstone in predicting sound transmission loss, yet it neglects the constraints of causal dispersion. Current causality-based theories, such as the Rozanov limit, are applicable only to one-port reflective absorbers. Here, we derive a universal sum rule governing causal scattering in acoustic systems, establishing a rigorous analogy to the Baldin sum rule in
quantum field theory. This relation reveals that the integral of the extinction cross-section is fundamentally locked by the scatterer's static effective mass and stiffness, which is validated numerically using seminal examples of
underwater metamaterials. Furthermore, the proposed sum rule predicts an optimal condition for an anomalously broadened transmission loss bandwidth, as experimentally observed through the spectral shaping effect of an acoustic Fano resonator. Our findings open up an unexplored avenue for enhancing the scattering bandwidth of passive metamaterials.
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All authors Sichao Qu, Zixiong Yu, Erqian Dong, Min Yang, Nicholas X. Fang
Materials Science
Contact resistance and interfacial engineering: Advances in high-performance 2D-TMD based devices
Xiongfang Liu, Kaijian Xing, Chi Sin Tang et al. (+7 more)
The development of advanced electronic devices is contingent upon sustainable material development and pioneering research breakthroughs. Traditional
semiconductor-based electronic technology faces constraints in material thickness scaling and energy efficiency. Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as promising candidates for next-generation nanoelectronics and optoelectronic applications, boasting high electron mobility, mechanical strength, and a customizable band gap. Despite these merits, the
Fermi level pinning effect introduces uncontrollable Schottky barriers at metal-2D-TMD contacts, challenging prediction through the Schottky-Mott rule. These barriers fundamentally lead to elevated contact resistance and limited current-delivery capability, impeding the enhancement of 2D-TMD transistor and integrated
circuit properties. In this review, we succinctly outline the
Fermi pinning effect mechanism and peculiar contact resistance behavior at metal/2D-TMD interfaces. Subsequently, highlights on the recent advances in overcoming contact resistance in 2D-TMDs devices, encompassing interface interaction and hybridization, van der Waals (vdW) contacts, prefabricated metal transfer and charge-transfer doping will be addressed. Finally, the discussion extends to challenges and offers insights into future developmental prospects.
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All authors Xiongfang Liu, Kaijian Xing, Chi Sin Tang, Shuo Sun, Pan Chen, Dong-Chen Qi, Mark B. H. Breese, Michael S. Fuhrer, Andrew T. S. Wee, Xinmao Yin
Materials Science
Wafer-scale High-k SrTiO3 Dielectrics with Rational Barrier-layer Design for Low Leakage and High Charge Density
Majid Mohseni, Shivasheesh Varshney, Seung Gyo Jeong et al. (+3 more)
High-k
oxides such as SrTiO3 promise large capacitance, but their dielectric response is often limited by leakage currents due to reduced bandgaps. We show that introducing a thin barrier layer beneath SrTiO3 is a simple and effective way to suppress leakage and increase charge density. Using hybrid molecular beam epitaxy, we grew uniform SrTiO3 films on Nb:SrTiO3, CaSnO3/Nb:SrTiO3, and 2-inch SiO2/p-Si stacks to directly compare how different barrier layers influence device behavior. Both CaSnO3 and SiO2 reduce leakage, but the ultra-wide-bandgap SiO2 layer enables much higher operating voltages, yielding charge densities exceeding 5x10^13 cm^-2 at room temperature - more than a fivefold enhancement compared to devices without a barrier layer. This improvement comes with a predictable trade-off: the lower dielectric constant of SiO2 reduces overall capacitance, making its thickness an important design parameter. Together, these results demonstrate that rational barrier-layer engineering - including wafer-scale integration on Si - provides a clear pathway to achieving higher charge densities in SrTiO3-based dielectric devices.
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All authors Majid Mohseni, Shivasheesh Varshney, Seung Gyo Jeong, Amber Walton, C. Daniel Frisbie, Bharat Jalan