Materials Science
CrSe_2 and CrTe_2 Monolayers as Efficient Air Pollutants Nanosensors
Hakkim Vovusha, Puspamitra Panigrahi, Yash Pal et al. (+4 more)
Nanosensors are critical in environmental monitoring, industrial safety, and public health by detecting specific hazardous gases like CO, NO, SO_2, and CH_4 at trace levels. This study uses density functional theory (DFT) calculations to examine the gas-sensing capabilities of chromium diselenide (CrSe_2) and chromium ditelluride (CrTe_2) monolayers through their structural and electronic responses to gas adsorption. Adsorption energy analysis shows that Te vacancy-induced CrTe_2 (VTe-CrTe_2) exhibits the strongest binding with energies of -1.52, -1.79, and -1.61 eV for CO, NO, and SO_2, respectively. Similarly, CrSe_2 has its values of -1.13, -1.17, -0.90, and -1.12 eV for CO, NO, SO_2, and CH_2, respectively, indicating suitability for reversible sensing. This study also investigates how substitutional doping of Ge, Sb, and Sn influences the sensing mechanism of CrSe_2 and CrTe_2 monolayers. Density of states (DOS) analysis highlights notable electronic changes around the
Fermi level, especially in VTe-CrTe_2 and Sb/Sn-doped CrTe_2, confirming their enhanced sensing abilities. Charge density difference analysis shows significant charge redistribution, with CrTe_2 experiencing stronger charge transfer effects than CrSe_2. Variations in electrostatic potential and work function further demonstrate the higher sensitivity of CrTe_2, particularly in its defective and doped forms, confirming its status as a superior material for gas sensing applications.
Read the full abstract ▾
All authors Hakkim Vovusha, Puspamitra Panigrahi, Yash Pal, Muhammad J. A. Shiddiky, Massimiliano Di Ventra, Hoonkyung Lee, Tanveer Hussain
Materials Science
Reproducible container solutions for codes and workflows in materials science
Dylan Bissuel, Léo Orveillon, Benjamin Arrondeau et al. (+15 more)
A computing solution combining the GNU Guix functional package manager with the Apptainer container system is presented. This approach provides fully declarative and reproducible software environments suitable for computational materials science. Its versatility and performance enable the construction of complete frameworks integrating workflow managers such as AiiDA, and Ewoks that can be deployed on HPC infrastructures. The efficiency of the solution is illustrated through several examples: (i) AiiDA workflows for automated
dataset construction and analysis as well as path-integral molecular dynamics based on ab initio calculations; (ii) workflows for the training of machine-learning interatomic potentials; and (iii) an Ewoks workflow for the automated analysis of coherent X-ray diffraction data in large-scale synchrotron facilities. These examples demonstrate that the proposed environment provides a reliable and reproducible basis for computational and data-driven research in materials science.
Read the full abstract ▾
All authors Dylan Bissuel, Léo Orveillon, Benjamin Arrondeau, Paulo Almeida De Mendonça, Irina Piazza, Martin Uhrin, Étienne Polack, Akshay Krishna Ammothum Kandy, David Martin-Calle, Jonathan Chapignac, Aadhityan Arivazhagan, Lorenzo Paulatto, Pierre-Antoine Bouttier, M.-I Richard, Thierry Deutsch, David Rodney, A M Saitta, Nöel Jakse
Materials Science
Nucleation suppression by charge screening on grain boundaries: a kinetic model for bulk imprint in polycrystalline ferroelectric thin films
Huanhuan Tian, Jianguo Yang and Ming Liu
The imprint effect, a significant reliability challenge in ferroelectric
memories, manifests as a shift in the coercive field during retention and endurance tests, ultimately degrading the usable
memory window. \rv{While traditional models attribute imprint primarily to charge screening at the interface between the dead layer and the ferroelectric film, the contribution from grain boundaries has been largely overlooked. This work advances a bulk imprint mechanism by establishing a phase-field model, which demonstrates that the tuning of domain
nuclei near grain boundaries via charge screening consistently explains the imprint process and aligns with key experimental trends.} These findings provide novel insights into the imprint process and advance the understanding of reliability issues in ferroelectric
memory devices.
Read the full abstract ▾
Materials Science · Cross-listed from cs.CE
Probabilistic Predictions of Process-Induced Deformation in Carbon/Epoxy Composites Using a Deep Operator Network
Elham Kiyani, Amit Makarand Deshpande, Madhura Limaye et al. (+7 more)
Fiber reinforcement and
polymer matrix respond differently to manufacturing conditions due to mismatch in coefficient of thermal expansion and
matrix shrinkage during curing of thermosets. These heterogeneities generate residual stresses over multiple length scales, whose partial release leads to process-induced deformation (PID), requiring accurate prediction and mitigation via optimized non-isothermal cure cycles. This study considers a unidirectional AS4 carbon fiber/amine bi-functional epoxy prepreg and models PID using a two-mechanism framework that accounts for thermal expansion/shrinkage and cure shrinkage. The model is validated against manufacturing trials to identify initial and boundary conditions, then used to generate PID responses for a diverse set of non-isothermal cure cycles (time-temperature profiles). Building on this physics-based foundation, we develop a data-driven surrogate based on Deep Operator Networks (DeepONets). A DeepONet is trained on a
dataset combining high-fidelity simulations with targeted experimental measurements of PID. We extend this to a Feature-wise Linear Modulation (FiLM) DeepONet, where branch-network features are modulated by external parameters, including the initial degree of cure, enabling prediction of time histories of degree of cure, viscosity, and deformation. Because experimental data are available only at limited time instances (for example, final deformation), we use transfer learning: simulation-trained trunk and branch networks are fixed and only the final layer is updated using measured final deformation. Finally, we augment the framework with Ensemble Kalman Inversion (EKI) to quantify uncertainty under experimental conditions and to support optimization of cure schedules for reduced PID in composites.
Read the full abstract ▾
All authors Elham Kiyani, Amit Makarand Deshpande, Madhura Limaye, Zhiwei Gao, Zongren Zou, Sai Aditya Pradeep, Srikanth Pilla, Gang Li, Zhen Li, George Em Karniadakis
Materials Science
Nonreciprocal Transport with Quantum Geometric Origin in Layered Hybrid Perovskite
Zihan Zhang, Sihan Chen, Mingfeng Chen et al. (+14 more)
Quantum geometry quantifies how the electron wavefunction evolves distinctly from conventional transport theory. In noncentrosymmetric materials, nonreciprocal transport with
quantum geometric origin remains prominent with localized charge independent of vanished group velocity. The discovery of such nonreciprocal and nonlinear responses was realized by recent advances in two-dimensional materials. As a promising candidate, the electronic structure and
symmetry of layered hybrid perovskites can be deliberately designed and manipulated by incorporating selected organic ligands. Despite the observation of exotic photogalvanic effects and
chiral optical effects, the underlying mechanism how these nonlinear responses are enabled in the multi-
quantum well structures remained unclear. Here we demonstrated the
quantum geometric origin for interlayer spontaneous photocurrent in (PEA)2PbI4. Contrary to assumptions that charge transport across the 2D planes is limited, we observed a spontaneous photocurrent along this crystalline orientation. Theoretical analysis using a tight-binding model identifies shift current as the microscopic origin. This
quantum geometric effect is enabled by ionic displacements from centrosymmetric coordinates and enhanced by multiband transition high-density bands of the layered hybrid
crystal. We anticipate that such unique low-dimensional systems with structure can provide fertile ground for discovering novel optoelectronic functionalities.
Read the full abstract ▾
All authors Zihan Zhang, Sihan Chen, Mingfeng Chen, Jee Yung Park, Gang Shi, Kaitai Xiao, Swati Chaudhary, Alejandro T. Busto, Kenji Watanabe, Takashi Taniguchi, Peng Xiong, Xiao-Xiao Zhang, Efstratios Manousakis, Letian Dou, Xi Wang, Cyprian Lewandowski, Hanwei Gao
Materials Science
Rapid synthesis of dual-element isotope-enriched alpha-MoO3 crystals by reactive vapor transport
Ryan W. Spangler, Jacob M. Shusterman, Anton V. Ievlev et al. (+3 more)
In this work, we develop a rapid reactive vapor transport technique to efficiently utilize limited isotopically pure precursors, particularly gaseous 18O2, and synthesize mm-scale, high-quality
crystals within few-minute growth durations. We unlock this capability by using metallic molybdenum precursors with high source temperatures (900 C) and total pressures (1 atm) to maximize precursor efficiency and yield. Subsequently, we grow MoO3 single
crystals with high and uniform enrichment levels of 98Mo and 18O isotopes in several different permutations. As probed by Raman spectroscopy, modest and significant
phonon energy
redshifts occur following 98Mo and 18O enrichment, respectively. By demonstrating control over both molybdenum and oxygen isotopic fractions, we establish a powerful tool to advance nanophotonics and thermal management goals using MoO3. This work is motivated by the possibility to enhance and engineer
lattice vibrational mode phenomena including thermal conduction and
hyperbolic phonon polariton (HPhP) dispersion, with particular interest in comparing the effects of light and heavy element enrichment.
Read the full abstract ▾
All authors Ryan W. Spangler, Jacob M. Shusterman, Anton V. Ievlev, Patrick E. Hopkins, Joshua D. Caldwell, Jon-Paul Maria
Materials Science
Transition from population- to coherence-dominated nondiffusive thermal transport
Laurenz Kremeyer, Bradley J. Siwick and Samuel Huberman
Deviations from diffusive heat transport in high thermal conductivity crystalline
insulators are generally understood within the framework of the
phonon Boltzmann Transport Equation. However, for low thermal conductivity materials with large primitive
cells or strong anharmonicity, the recently developed Wigner Transport Equation is more appropriate as it includes tunnelling between overlapping
phonon bands. In this work, via solutions to the Wigner Transport Equation, we develop a scheme to obtain the dynamics of the
phonon populations and coherences as a function of an arbitrary heat source. The approach is applied to predict size effects and dynamical thermal conductivities in CsPbBr$_\text{3}$ and La$_\text{2}$Zr$_\text{2}$O$_\text{7}$ using first-principles data as input. We predict significant deviations from the bulk thermal conductivity in these materials at length scales on the order of hundreds of nanometers to a few microns at room temperature, well within the reach of direct observation using current experimental techniques.
Read the full abstract ▾
Materials Science · Cross-listed from physics.optics
Thermoplasmonics under optically coupled regime: A Numerical Study of Dimers, Nanolenses, and Switchable Clusters
José Luis Montaño Priede and Marek Grzelczak
The management of thermal effects in plasmonic nanostructures is frequently viewed as a detrimental waste rather than a useful, controllable entity. We show that optical coupling of plasmonic nanoparticles enables precise spatiotemporal control over nanoscale heating. Through numerical investigation of experimentally-achievable systems from individual nanoparticles and dimers to nanolenses and switchable clusters, we demonstrate how plasmon hybridization and near-field coupling dictate the magnitude and spatial distribution of temperature. Our results highlight the critical role of polarization and gap distance in tuning the thermal output of dimers, the ability of a trimer nanolens to focus heat into a sub-diffraction volume, and the pronounced thermal difference in a switchable nanoparticle cluster. This work establishes a framework for designing advanced thermoplasmonic systems where heat is not merely a detriment, but a dynamically controllable element for applications in catalysis, health, or active photonic devices.
Read the full abstract ▾
Materials Science
I. I. Gimazov, D. E. Zhelezniakova, R. B. Zaripov et al. (+7 more)
We report results of electron
spin resonance (ESR) measurements in single
crystals of EuSn$_2$As$_2$. In the temperature range of
antiferromagnetic (AFM) ordering of Eu atoms, $T \leq T_N\approx 24$\,K, the ESR signal splits into two resonance lines, one of which, at high-field (or low-frequency), is the conventional acoustic AFM resonance mode that occurs at temperatures below $T_N$. The lower-field (high-frequency) line, as we have proven here, is the
ferromagnetic resonance associated with the presence in the layered AFM
crystal of a small amount ($\sim 3\%$) of planar nanodefects with a non-zero
ferromagnetic (FM) moment. The existence of
ferromagnetic nano-inclusions in the bulk of the
antiferromagnetic compound makes EuSn$_2$As$_2$ a peculiar example of a natural
magnetic metamaterial. We believe that the planar FM nanodefects are also inherent in other layered AFM compounds, which explains often observed increase in their
magnetic susceptibility upon cooling at $T< T_N\rightarrow 0$.
Read the full abstract ▾
All authors I. I. Gimazov, D. E. Zhelezniakova, R. B. Zaripov, Yu. I. Talanov, A. Yu. Levakhova, A. V. Sadakov, K. S. Pervakov, V. A. Vlasenko, A. L. Vasiliev, V. M. Pudalov
Materials Science
Electronic and optical properties of native point defects in CuInS$_2$ and CuGaS$_2$
Henry Phillip Fried, Daniel Barragan-Yani and Ludger Wirtz
We present a detailed study of common intrinsic defects in CuInS$_2$ and CuGaS$_2$ using the Heyd, Scuseria and Ernzerhof (HSE) hybrid functional scheme. The impact of the two HSE parameters, $\alpha$ and $\omega$ on the band gap and compliance with the generalized Koopmans'
theorem is investigated. Using the formation energy formalism and calculated thermodynamic charge-transition levels, we assess the electronic properties of the defects and explore the connection of charge-transition levels with optical-transition levels. Calculated Franck-Condon shifts for emission highlight the importance of
lattice relaxation for the attribution of defects to luminescence peaks. Our results show that once these effects are included, predictions become closer to photoluminescence measurements available in literature.
Read the full abstract ▾
Materials Science · Cross-listed from cond-mat.str-el
The classical-quantum disproportionation transition and magnetic ordering in RNiO$_3$ nickelates
A.S. Moskvin and Yu.D. Panov
The
insulator-quasi-metal (bad metal) transition observed in Jahn-Teller (JT) magnets orthonickelates RNiO$_3$ (R = rare earth, or yttrium Y) is considered a canonical example of the Mott transition, traditionally described in the framework of Hubbard's $U-t$ model. However, in reality, the insulating phase of nickelates is the result of charge disproportionation (CD) with the formation of a system of
spin-triplet ($S = 1$) electron [NiO$_6$]$^{10-}$ and spinless ($S = 0$) hole [NiO$_6$]$^{8-}$ centers, equivalent to a system of effective
spin-triplet composite
bosons moving in a nonmagnetic
lattice. The effective CD-phase
Hamiltonian takes into account local ($U$) and nonlocal ($V$) correlations, and the transfer of composite
bosons ($t_b$). Within the framework of the effective field approximation, we have shown the existence of two types of CD phases: the high-temperature classical paramagnetic CO-phase of charge ordering of electron and hole centers, and the low-temperature
magnetic quantum CDq phase with charge and
spin density transfer between electron and hole centers, with ”uncertain valence” [NiO$_{6}$]$^{(9\pm\delta)-}$ ($0 \le \delta \le 1$) and
spin density $(1 \pm \delta)/2$ NiO$_6$-centers. In the classical CO phase,
spin-triplet electron centers are surrounded by the nearest nonmagnetic hole centers, which ”turns off” the strong superexchange interaction of the nearest neighbors. The
magnetic ordering in the
quantum CDq phase is determined by a strong traditional superexchange and an unusual bosonic double exchange mechanism.
Read the full abstract ▾
Materials Science
Impact of an electron Wigner crystal on exciton propagation
Daniel Erkensten, Alexey Chernikov and Ermin Malic
The strong Coulomb interaction in 2D materials facilitates the formation of tightly bound
excitons and charge-ordered phases of matter. A prominent example is the formation of a crystalline phase from free charges due to mutual Coulomb repulsion, known as the Wigner
crystal. While
exciton-electron interactions have been used as a sensor for Wigner crystallization, its impact on
exciton properties has been poorly understood so far. Here, we show that the weak potential induced by periodically ordered Wigner
crystal electrons has a major impact on
exciton propagation, albeit having only a minor influence on
exciton energy. The effect is tunable with carrier density determining the Wigner
crystal confinement and temperature via thermal occupation of higher subbands. Our work provides microscopic insights into the interplay between
excitons and charge-ordered states identifying key signatures in
exciton transport, and establishes a theoretical framework for understanding
exciton propagation in the presence of strong electronic correlations.
Read the full abstract ▾
Materials Science
Computational prediction of ferromagnetic AT6X6 kagome compounds
Shiya Chen, Zhen Zhang, Vladimir Antropov et al. (+1 more)
We present a systematic high-throughput density-functional-theory investigation of the structural and
magnetic stability of 312 substitutional compounds in the
magnetic kagome AT6X6 family. Our screening confirms the stability of many previously reported structures and predicts several additional stable candidates. Within collinear
spin configurations, we find that Fe-based systems predominantly adopt
antiferromagnetic ground states, whereas Mn-based analogues exhibit a more balanced distribution between
ferromagnetic and
antiferromagnetic order. For compounds exhibiting several nearly degenerate collinear configurations, we analyze the nature of their
magnetic ground states, assess the possible emergence of non-collinear order, and discuss the limitations and uncertainties inherent to standard density-functional approaches. Our electronic-structure analysis further reveals that newly predicted
ferromagnetic kagome systems display characteristic features of topological metals, with rich
magnetic configurations that can be tuned by chemical substitution. Overall, these
ferromagnetic kagome compounds constitute a broad and still largely unexplored materials platform for the emergence of exciting magneto-transport phenomena.
Read the full abstract ▾
All authors Shiya Chen, Zhen Zhang, Vladimir Antropov, Yang Sun
Materials Science · Cross-listed from cond-mat.soft
Towards Animate Droplets: Active, Adaptive, and Autonomous
Joe Forth, Robert Malinowski and Giorgio Volpe
Droplets, sub-millilitre
liquid volumes with at least one interface, have traditionally served as compartments for storing, transporting, and delivering materials. Beyond familiar applications in food, coatings, and consumer goods, they find cutting-edge use in energy storage, sensing, and tissue engineering. The next frontier is their integration into animate matter, emerging materials defined by their levels of activity, adaptiveness, and autonomy. Easy to produce and dispense or print into complex structures, and with enormous chemical versatility, droplets are ideal building blocks for animate matter. In this Perspective, we outline a roadmap for advancing animacy in droplets and call for a more concerted effort to integrate novel mechanisms for motility, sensing, and decision-making into droplet design. Although research on active droplets spans more than a century, achieving true autonomy, where droplets process multiple stimuli and respond without external control, remains a central challenge. We hope to inspire interdisciplinary collaboration towards applications in consumer goods, microfluidics, adaptive optics, tissue engineering, and soft robotics.
Read the full abstract ▾
Materials Science · Cross-listed from cond-mat.mes-hall
Gate-Tunable Giant Negative Magnetoresistance in Tellurene Driven by Quantum Geometry
Marcello B. Silva Neto, Chang Niu, Marcus V. O. Moutinho et al. (+5 more)
Negative magnetoresistance in conventional two-dimensional electron gases is a well-known phenomenon, but its origin in complex and topological materials, especially those endowed with
quantum geometry, remains largely elusive. Here, we report the discovery of a
giant negative magnetoresistance, reaching a remarkable $- 90\%$ of the resistance at zero
magnetic field, $R_0$, in $n$-type tellurene films. This record-breaking effect persists over a wide
magnetic field range (measured up to $35$ T) at cryogenic temperatures and is suppressed when the chemical potential shifts away from the Weyl node in the conduction band, strongly suggesting a
quantum geometric origin. We propose two novel mechanisms for this phenomenon: a
quantum geometric enhancement of
diffusion and a magnetoelectric
spin interaction that locks the
spin of a Weyl
fermion, in cyclotron motion under crossed electric $\boldsymbol{\cal E}$ and
magnetic ${\bf B}$ fields, to its guiding-center drift, $(\boldsymbol{\cal E}\times{\bf B})\cdot\sigma$. We show that the time integral of the velocity auto-correlations promoted by the
quantum metric between the
spin-split conduction bands enhance
diffusion, thereby reducing the resistance. This mechanism is experimentally confirmed by its unique magnetoelectric dependence, $\Delta R_{zz}(\boldsymbol{\cal E},{\bf B})/R_0=-\beta_{g}(\boldsymbol{\cal E}\times{\bf B})^2$, with $\beta_{g}$ determined by the
quantum metric. Our findings establish a new,
quantum geometric and non-Markovian
memory effect in magnetotransport, paving the way for controlling electronic transport in complex and topological matter.
Read the full abstract ▾
All authors Marcello B. Silva Neto, Chang Niu, Marcus V. O. Moutinho, Pierpaolo Fontana, Claudio Iacovelli, Victor Velasco, Caio Lewenkopf, Peide D. Ye
Materials Science
Developing a valence force field model for wurtzite semiconductors by exploiting similarities with [111]-oriented zinc blende systems: The case of wurtzite boron nitride, III-N materials and (B,In,Ga)N alloys
Aisling Power, Cara-Lena Nies and Stefan Schulz
Controlling the
crystal phase and
lattice mismatch of
semiconductors offers a powerful route to engineer electronic and optical properties of
heterostructures. As a consequence,
semiconductors in the wurtzite phase are increasingly sought after, superseding the thermodynamically favored cubic zinc blende phase. Empirical atomistic modeling, required for large scale simulations of
heterostructures and their properties, relies heavily on valence force field (VFF) methods to find the
equilibrium atomic positions in an
alloy. For zinc blende
crystals, VFF models are well-established. In the case of wurtzite, such parameters are frequently adopted without rigorous analysis, despite subtle but consequential differences from the zinc blende structure. Such an approach can compromise accuracy in describing material properties, since the structural differences between zinc blende and wurtzite directly influence electronic and optical characteristics. Based on the analytical VFF model by Tanner et al., and using structural similarities between wurtzite and [111]-oriented zinc blende, we construct a wurtzite VFF without introducing additional parameters. Our framework relies on analytic expressions and minimization routines to project zinc blende models onto wurtzite systems. Beyond elastic tensors, we train the model to reproduce bond length asymmetries and band gaps by using output of the VFF model in density functional theory calculations. Applied to wurtzite III-N compounds and BN, the model accurately reproduces targeted observables but also properties it has not been trained on, including the internal parameter u. We further validate the model on highly mismatched
alloys such as (B,Ga)N and (B,In,Ga)N, exhibiting good agreement between VFF and density functional theory results when using identical supercells in these calculations.
Read the full abstract ▾
Materials Science · Cross-listed from cond-mat.mes-hall
Transport of Dirac magnons driven by gauge fields
Luis Fernández, Ka Shen, Leandro O. Nascimento et al. (+3 more)
We present a unified
quantum field theory for Dirac
magnons coupled to emergent gauge fields. At zero temperature, any space- and time-dependent gauge perturbation drives
magnons out of
equilibrium, generating
spin currents and
magnon accumulation without conventional thermal or chemical potential gradients. For a honeycomb ferromagnet, we derive closed-form expressions for the induced density and current. In the DC limit, the transverse
spin conductivity quantizes to $\sigma^{xy}=\alpha^2\text{sgn}(m)\hbar/4\pi$, a magnonic analog of the
quantum Hall effect, where $m$ is the topological
magnon mass and $\alpha$ a dimensionless coupling constant. In the AC regime, the conductivity exhibits a sharp resonance when the drive frequency matches the topological gap $\Delta$, signaling interband transitions. Our work establishes gauge fields as a versatile tool for controlling
magnon transport and reveals topologically protected quantized responses.
Read the full abstract ▾
All authors Luis Fernández, Ka Shen, Leandro O. Nascimento, Van Sérgio Alves, Roberto E. Troncoso, Nicolas Vidal-Silva
Materials Science · Cross-listed from cond-mat.mes-hall
Chirality Imprinting and Spin-texture Tunability in Conformally Coated 3D Magnetic Nanostructured Metamaterials
Alexander Roberts, Huixin Guo, Joseph Askey et al. (+4 more)
Three-dimensional (3D)
magnetic nanostructures offer unprecedented opportunities for engineering emergent
spin textures, but controlling their configuration remains a central challenge. Here we show that conformally coated Ni Nanotubes arranged in a woodpile geometry with
lattice spacings ranging from 800 to 1200 nm, realised by two-
photon lithography and atomic layer deposition, exhibit a geometry-tuneable balance between
chiral and axial states.
Magnetic force microscopy on the top layer of the 3D woodpile reveals that few-layer systems exhibit a
chiral contrast whilst increasing the number of stacked layers drives a transition to an axial configuration with the change in state populations depending strongly on
lattice spacing. Micromagnetic simulations demonstrate that chirality is not intrinsic to isolated tubes but is imprinted by
spin textures formed in the substrate sheet film, which couple into the 3D network. As the sheet-film influence diminishes with increasing layer number, dipolar interactions dominate and stabilise the axial state. This two-stage mechanism of chirality imprinting followed by increasingly dominant dipolar interactions, provides clear control parameters for tailoring
spin-texture populations. Our results establish conformally coated woodpiles as a reconfigurable 3D
ferromagnetic metamaterial platform that can be exploited for data storage, magnonics, and neuromorphic computing.
Read the full abstract ▾
All authors Alexander Roberts, Huixin Guo, Joseph Askey, Vani Lanka, Arjen van den Berg, Dirk Grundler, Sam Ladak
Materials Science
Heterostructure Design in Two-Dimensional Perovskites by Sequential Recrystallization
Mehrdad Faraji, Alexander Schleusener, Sirous Khabbaz Abkenar et al. (+9 more)
Low-dimensional metal halide perovskites provide exciting opportunities to fabricate new
semiconductor materials.
Semiconductor technology relies on electronic heterojunctions, and cost-efficient and flexible approaches to realize functional
heterostructures are of fundamental importance. Lateral
heterostructures define the energy landscape in the plane of the semiconducting
lattice in such 2D materials, representing an ideal platform to tailor energy barriers and to control charge carrier flow. Here, we demonstrate a versatile one-pot synthesis to fabricate a large variety of 2D perovskite
heterostructures based on different halides and/or metal cations. Exploiting sequential crystallization of different 2D perovskites, and playing with the composition and injection events of the materials, enables the design of diverse
heterostructure architectures including multiple heterojunctions. We obtain crystalline quality of the heterojunctions, multicolor emission, and optical coupling between the different
heterostructure regions. We foresee that the design freedom of our method will stimulate the development of novel optoelectronic devices where electronic band engineering is crucial.
Read the full abstract ▾
All authors Mehrdad Faraji, Alexander Schleusener, Sirous Khabbaz Abkenar, Andrea Griesi, Mattia Lizzano, Sudhir Kumar Saini, Aswin V. Asaithambi, Liberato Manna, Matteo Lorenzoni, Mirko Prato, Giorgio Divitini, Roman Krahne
Materials Science
Computational tuning of the elastic properties of low- and high-entropy ultra-high temperature ceramics
Samuel J. Magorrian, Ljiljana Stojanović, Lara Kabalan et al. (+4 more)
Ultra-high temperature ceramics (UHTCs) represent a class of crystalline materials for extreme environments. They can withstand extremely high temperatures but are mechanically difficult to work with due to their inherent brittleness. Mixture compounds, in particular high-
entropy mixtures, offer a pathway to tune the physical properties of UHTCs such as their elastic constants. Here we fine-tune the MACE-MPA-0 universal machine-learning potential on rocksalt carbide UHTCs containing group IV-V metals and demonstrate that not only do the elastic constants deviate from the rule of mixtures approximation in the high-
entropy limit, but also in the low-
entropy limit of binary and ternary mixtures. We find that this is caused by distortion imposed by the
lattice mismatch, enabling the tuning of the physical properties of UHTC mixtures in both low- and high-
entropy compounds. We identify a three-component mixture compound, HfCVCZrC, as the best balance between synthesizability and toughness, and apply our developed MACE-UHTC model to identify a range of non-equimolar candidate compositions of this compound which may enable the synthesis of a mixture UHTC with a Young's modulus up to 40 GPa below that of ZrC.
Read the full abstract ▾
All authors Samuel J. Magorrian, Ljiljana Stojanović, Lara Kabalan, Ardita Shkurti, Richard N. White, Fabian L. Thiemann, Viktor Zólyomi
Materials Science · Cross-listed from cs.LG
PolySet: Restoring the Statistical Ensemble Nature of Polymers for Machine Learning
Khalid Ferji
Machine-learning (ML) models in
polymer science typically treat a
polymer as a single, perfectly defined molecular graph, even though real materials consist of
stochastic ensembles of chains with distributed lengths. This mismatch between physical reality and digital representation limits the ability of current models to capture
polymer behaviour. Here we introduce PolySet, a framework that represents a
polymer as a finite, weighted ensemble of chains sampled from an assumed molar-mass distribution. This ensemble-based encoding is independent of chemical detail, compatible with any molecular representation and illustrated here in the homopolymer case using a minimal
language model. We show that PolySet retains higher-order distributional moments (such as Mz, Mz+1), enabling ML models to learn tail-sensitive properties with greatly improved stability and accuracy. By explicitly acknowledging the statistical nature of
polymer matter, PolySet establishes a physically grounded foundation for future
polymer machine learning, naturally extensible to copolymers, block architectures, and other complex
topologies.
Read the full abstract ▾
Materials Science · Cross-listed from quant-ph
Intense-Laser Nondipole-Induced Symmetry Breaking in Solids
Asger Weeth and Lars Bojer Madsen
High-harmonic spectroscopy in solids gives insight into the inner workings of solids, such as reconstructing band structures or probing the topological phase of materials. High-harmonic generation (HHG) is a highly non-linear phenomena and simulations guide interpretation of experimental results. These simulations often rely on the electric dipole approximation, even though the driving fields enter regimes that challenge its accuracy. Here, we investigate effects of including nondipole terms in the light-matter coupling in simulations of HHG in materials with both topologically trivial and non-trivial phases. We show how the inclusion of nondipole terms breaks dipole selection rules, allowing for new polarizations of the generated light. Specifically we find that helicity, completely absent in the dipole approximation, is induced by the nondipole extension, and that this helicity is dependent on the topological phase of the material.
Read the full abstract ▾
Materials Science
Hydrothermal synthesis of SnO2 particles for the degradation of Methylene Blue (MB) dye in presence of sunlight
Komal Singh, Jyoti Sindkar, Mrunal Ramdasi et al. (+2 more)
Three distinct samples were proceed through synthesis utilizing the hydrothermal method to develop tin dioxide (SnO2) nanoparticles. Consistency in all other parameters was ensured by maintaining a constant temperature and time throughout the synthesis. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to examine how the surfactant affected the structural, morphological, and crystallographic characteristics. A tetragonal rutile SnO2 phase was confirmed to have formed by XRD investigation, with high crystallinity indicated by strong diffraction peaks. Higher precursor concentration samples showed aggregation, indicating that the smaller size of the nanoparticles caused them to interact. These findings show that changing the surfactant has a major impact on the crystallinity, size, and shape of SnO2 nanoparticles, which makes this technique establish for certain uses, including energy storage, gas sensors, and photocatalysis. Additionally, we examined the photocatalytic activity of the aforementioned samples, indicating from the UV-vis characterization results that the sample containing PEG as a surfactant performs better than others.
Read the full abstract ▾
All authors Komal Singh, Jyoti Sindkar, Mrunal Ramdasi, Vrishali Jadhav, Rohidas B. Kale
Materials Science
Quantum-inspired Chemical Rule for Discovering Topological Materials
Xinyu Xu, Rajibul Islam, Ghulam Hussain et al. (+5 more)
Topological materials exhibit unique electronic structures that underpin both fundamental
quantum phenomena and next-generation technologies, yet their discovery remains constrained by the high computational cost of first-principles calculations and the slow, resource-intensive nature of experimental synthesis. Recent machine-learning approaches, such as the heuristic topogivity rule, offer a data-driven pre-screening tool by quantifying each element's intrinsic tendency toward topological behavior. Here, we develop a hybrid
quantum-classical neural network (HQCNN) that extends this rule into a
quantum-inspired formulation. Within this framework, the HQCNN maps compositional descriptors to
quantum probability amplitudes, naturally introducing pairwise inter-element correlations inaccessible to classical heuristics. The physical validity of these correlations is substantiated by constructing an equivalent complex-valued neural network (CVNN), confirming both the consistency and interpretability of the formulation. Retaining the simplicity of chemical
reasoning while
embedding quantum-native features, our
quantum-inspired rule enables efficient and generalizable topological classification. High-throughput screening combined with first-principles (DFT) validation reveals five previously unreported topological compounds, demonstrating the enhanced predictive power and physical insight afforded by
quantum-inspired heuristics.
Read the full abstract ▾
All authors Xinyu Xu, Rajibul Islam, Ghulam Hussain, Yangming Huang, Xiaoguang Li, Pavlo O. Dral, Arif Ullah, Ming Yang
Materials Science
Topological descriptor for interpretable thermal transport prediction in amorphous graphene
Kosuke Yamazaki, Takuma Shiga, Kumpei Shiraishi et al. (+1 more)
Understanding and predicting thermal transport in disordered materials remains a significant challenge due to the absence of periodicity and the complex nature of medium-range structural motifs. In this work, we investigate amorphous
graphene and demonstrate that persistent homology, a topological data analysis technique, can serve as a physically interpretable structural descriptor for predicting thermal conductivity. We first show that ridge regression using persistent homology descriptors achieves high prediction accuracy. To gain physical insight into the prediction process, we perform inverse analysis by mapping the regression coefficients back onto the persistence diagrams. This reveals that distorted hexagonal and triangular motifs are strongly correlated with reduced thermal conductivity. A further comparison with the spatial distribution of localized vibrational modes supports the physical interpretation that these motifs suppress thermal transport. Our findings highlight that persistent homology not only enables accurate prediction of physical properties but also uncovers meaningful structure-property relationships in two-dimensional amorphous materials. This approach offers a promising framework for interpretable machine-learning models in materials science.
Read the full abstract ▾
All authors Kosuke Yamazaki, Takuma Shiga, Kumpei Shiraishi, Emi Minamitani
Materials Science
3D lattice Monte Carlo modeling of morphology formation of Si/SiOx nanocomposites during phase separation of nonstoichiometric Si oxide films
Ivan Oliinyk and Andrey Sarikov
In this paper, a three-dimensional
lattice model based on the Monte Carlo approach is presented. This model is developed to investigate the kinetics of morphology change during phase separation in nonstoichiometric Si
oxide (SiOx, x < 2) films. The model takes into account the SiOx local atomic structure and probabilistic migration of oxygen atoms driven by the tendency of free energy minimization. The influence of the initial SiOx stoichiometry index x and film thickness on the morphology of the precipitated Si phase in the Si
oxide matrix is analyzed. The morphology of the Si phase is shown to critically depend on the initial SiOx stoichiometry. Namely, isolated Si nanoparticles form at low excess Si content (x >= 1.4), while interconnected Si networks always appear at x <= 0.8. A dimensional effect on the morphology of the Si phase is revealed. Namely, reducing the film thickness imposes
geometric constraints on the Si network formation. The percolation threshold is found to shift from xp ~= 1.35 for the bulk-like SiOx layers to xp ~= 0.85 for the quasi-two-dimensional films. The transition to the bulk material behavior is observed at a SiOx thickness of approximately 4.2 nm.
Read the full abstract ▾
Materials Science
Enhanced THz emission and exciton transfer in monolayer MoS2/GaAs heterostructures
C. Abinash Bhuyan, Anil K. Chaudhary, Kishore K. Madapu et al. (+2 more)
For designing an efficient terahertz (THz) emitter, the defect density of the
semiconductors is smartly increased to reduce carrier lifetime, which subsequently lowers the overall power output of the
semiconductor. To overcome this fundamental trade-off, this study presents a novel approach, by integrating a direct band gap 2D
semiconductor such as monolayer MoS2 (1L-MoS2) with a well-known THz emitter, low-temperature-grown gallium arsenide (GaAs). The fabricated hybrid 2D/3D vertical van der Waals
heterostructure showed a 15% higher THz emission compared to bare GaAs due to phase-coherent addition of second-order non-linear susceptibility, and overall enhancement in the electric field of
laser. The photoluminescence (PL) enhancement factor of 2.38 in
heterostructures at GaAs emission energy of 1.42 eV. However, the substantial quenching of PL emission for 1L-MoS2 at the energy of 1.84 eV, is attributed to the Dexter-type
exciton transfer mechanism at type-I band
alignment. THz time-domain spectroscopy reveals a significant increase in optoelectronic properties, such as optical conductivity becoming doubled, and a 50% reduction in absorption coefficients. The study introduces a new route for fabricating large-area and compact mixed-dimensional van der Waals
heterostructures, which can be used to enhance the efficiency of conventional
semiconductor technologies and THz-based optoelectronic devices.
Read the full abstract ▾
All authors C. Abinash Bhuyan, Anil K. Chaudhary, Kishore K. Madapu, P. Naveen Kumar, Sandip Dhara
Materials Science
Phase-field simulation of domain switching in ferroelectric trilayer films under bending-induced strain gradient
Changqing Guo, Letao Yang, Jing Wang et al. (+1 more)
Flexible ferroelectrics possess significant potential for wearable electronics and bio-inspired devices, yet their electromechanical coupling mechanisms under dynamic bending remain elusive. This study employs phase-field simulations to investigate the effects of bending deformation on domain structures and macroscopic ferroelectric responses in (SrTiO3)10/(PbTiO3)10/(SrTiO3)10 trilayer films. By constructing computational models for upward-concave (U-shaped) and downward-concave (N-shaped) configurations, we analyze the regulation of polarization patterns by strain distributions under varying
curvature radii. The results demonstrate that the two bending modes generate opposite through-thickness strain gradients: U-shaped bending produces compressive strain in the upper layer and tensile strain in the lower, while N-shaped bending yields the reverse. These inhomogeneous strains drive distinct polarization reconfigurations within the PTO layer. While stable
vortex-antivortex pairs persist at moderate
curvatures, reducing the bending radius triggers divergent topological transitions – U-shaped bending transforms
vortex pairs into zigzag-like domains, whereas N-shaped bending promotes out-of-plane c-domain
evolution. Crucially, bending-induced strain gradients generate transverse flexoelectric fields that markedly modulate hysteresis loops. U-shaped bending introduces a negative flexoelectric field, shifting loops rightward and suppressing maximum polarization Pmax. In contrast, N-shaped bending generates a positive field, shifting loops leftward and enhancing Pmax. Furthermore, analysis of polarization switching reveals that bending mediates domain-
evolution pathways and reversal dynamics.
Read the full abstract ▾
All authors Changqing Guo, Letao Yang, Jing Wang, Houbing Huang
Materials Science
Experimental Demonstration and Transformation Mechanism of Quenchable Two-dimensional Diamond
Jiayin Li, Guoshuai Du, Lili Zhao et al. (+14 more)
Two-dimensional (2D) diamond has aroused tremendous interest in nanoelectronics and optoelectronics, owing to its superior properties and flexible characteristics compared to bulk diamond. Despite significant efforts, great challenges lie in the experimental synthesis and transformation conditions of 2D diamond. Herein, we have demonstrated the experimental preparation of high quality 2D diamond with controlled thickness and distinguished properties, realized by
laser-heating few-layer
graphene in diamond anvil
cell. The quenched 2D diamond exhibited narrow T2g Raman peak (linewidth ~3.6 cm-1) and intense photoluminescence of SiV- (linewidth ~6.1 nm) and NV0 centers. In terms of transformation mechanism, atomic structures of hybrid phase interfaces suggested that the intermediate rhombohedral phase subtly mediate hexagonal graphite to cubic diamond transition. Furthermore, the tunable optical bandgap and thermal stability of 2D diamond sensitively depend on its sp3 concentration. We believe our results can shed light on the structural design and preparation of many carbon allotropes and further uncover the underlying transition mechanism.
Read the full abstract ▾
All authors Jiayin Li, Guoshuai Du, Lili Zhao, Wuxiao Han, Jiaxin Ming, Shang Chen, Pengcheng Zhao, Lu Bai, Jiaohui Yan, Yubing Du, Jiajia Feng, Hongliang Dong, Ke Jin, Weigao Xu, Bin Chen, Jianguo Zhang, Yabin Chen
Materials Science
Magnetic field-tuned size and dual annihilation pathways of chiral magnetic bobbers
S. Y. Lu, Y. F. Duan, D. X. Yu et al. (+1 more)
Magnetic chiral bobbers (CBs) are three-dimensional (3D) topological
spin textures that consist of a tapered skyrmion tube terminating in a Bloch point, promising applications in high-density spintronics. However, the mechanisms controlling their size and the dynamics of their annihilation are still not fully understood. In this study, we present an analytical model that predicts the radius $R$ of the CB as a function of the external
magnetic field, the Dzyaloshinskii-Moriya interaction (DMI), the
magnetic anisotropy, and the exchange interaction. The micromagnetic simulations validate this model across a broad range of parameters. We also identify two mechanisms of annihilation of CBs: (i) a droplet-like instability that occurs under rapid changes in the
magnetic field, which we describe using a proposed
magnetic Weber number $We$ and its critical field step scaling; and (ii) Bloch point depinning mechanism at interfaces, for which we determine the threshold
magnetic field $B_{\text{th}}$ for annihilation. Importantly, we uncover a novel fragmentation pathway in which CBs transform into skyrmion tubes, then into half-CBs, and finally into
ferromagnetic states. These findings lay the groundwork for understanding and manipulating 3D CBs as next-generation devices.
Read the full abstract ▾
All authors S. Y. Lu, Y. F. Duan, D. X. Yu, H. M. Dong