arXiv subjects

Boyang Zhao

Publications and source records attributed to Boyang Zhao.

At least 19 recordsLinked to original sources

arXiv2026

RTE-FM-Dehazer: Radiative Transfer Equation Inspired Flow Matching for Real-World Image Dehazing

Single-image dehazing aims to recover a clear scene from a hazy image and is generally formulated as an image-to-image translation task; however, it faces two limitations. Its performance depends heavily on the haze-formation priors embedded in the model. Prevailing methods adopt the Atmospheric Scattering Model (ASM), whose assumptions of single scattering and homogeneous media are often violated, leading to residual haze and color drift. Moreover, large-scale real hazy/clear pairs are impractical to collect, and existing synthesis approaches fail to reproduce the full complexity of natural haze. To address these issues, we present RTE-FM-Dehazer, a novel dehazing approach, together with a scalable data pipeline. Unlike the ASM, the Radiative Transfer Equation (RTE) jointly accounts for both scattering and absorption, naturally accommodating the non-homogeneous, multiple-scattering media that characterize real hazy scenes. Motivated by the structural similarity between the RTE diffusion-absorption term and the ODE in flow matching, we introduce a diffusion-absorption regularizer derived from a reduced RTE, to steer the flow matching trajectory at each step. Next, leveraging modern vision-language models, we build an automated pipeline and release P-HAZE, a dataset of 50000 realistic hazy/clear pairs. Extensive evaluations demonstrate that RTE-FM-Dehazer, trained solely on P-HAZE, effectively eliminates artifacts like residual haze and color drift, exhibits strong cross-domain generalization, and achieves leading results on five real-world dehazing benchmarks.

cs.CV↗

arXiv2026

Patient-Specific Articulated Digital Twins from a Single Full-Body CT Scan

Patient-specific anatomical models provide individualized context for surgical planning, image-guided intervention, and algorithm development. However, most CT-derived models are static: they preserve the body configuration captured at scan time, but cannot represent how the same anatomy would appear after patient repositioning. This limitation is especially important for radiographic imaging, where appearance depends jointly on imaging geometry and patient pose. We present a proof-of-concept for constructing a patient-specific \emph{articulated} digital twin from a single full-body CT scan. The method fits a parametric human body model (SMPL) to obtain a patient-aligned kinematic scaffold, binds segmented bones and organs to an anatomy-aware rig, and retargets body-pose changes while preserving skeletal geometry. Using full-body CT scans from three subjects, the fitted scaffold achieved 15.8 $\pm$ 4.0 mm chamfer distance and 95.9 $\pm$ 1.8\% skeletal enclosure. Recomposition at the acquisition pose preserved major radiographic structure, with overall SSIM of 0.872 $\pm$ 0.016 and PSNR of 18.5 $\pm$ 1.4 dB across paired DRRs. Across unseen target poses, the resulting twins enabled articulation while maintaining high skeletal enclosure (94.4 $\pm$ 0.4\%). As a feasibility demonstration, we render the articulated twin as pose-dependent DRRs. These results suggest the feasibility of extending static, view-controllable CT simulation toward pose-controllable anatomical twins for future synthetic imaging and positioning studies.

cs.CV↗

arXiv2026

Probing lattice fluctuations using solid-state high-harmonic spectroscopy

Solid-state high-harmonic spectroscopy allows the study of strongly driven ultrafast electron dynamics. Microscopically, high harmonics are generated by strong-laser-field acceleration of electron-hole pairs through the lattice. At finite temperatures, atomic-scale structural fluctuations are ubiquitous and are expected to influence the electron-hole trajectories. Yet, the effect of thermal lattice fluctuations on solid-state high-harmonic generation (HHG) has not been quantified. Here, we demonstrate a profound sensitivity of HHG to thermal lattice fluctuations, by characterizing the temperature dependence of HHG in Re6Se8Cl2, a superatomic semiconductor. As the sample temperature is decreased, the high-harmonic yield exhibits a slow increase, followed by an abrupt increase below 50 K, consistent with the temperature at which lattice vibrations are strongly suppressed. Our calculations show that thermal lattice fluctuations both weaken the harmonic response from individual distorted configurations and induce phase dispersion across the ensemble, leading to a pronounced suppression of the coherently emitted harmonics. We show that this effect can be interpreted in terms of an effective electronic dephasing time that varies with temperature. Our results are relevant to dephasing in broad strong-field phenomena, including lightwave electronics and Floquet engineering. The wide tunability of superatomic crystals further enables materials-controlled strong-field physics.

cond-mat.mtrl-sci↗

arXiv2026

Structural Phase Separation Couples to Charge-Density-Wave Formation in Kagome Metal FeGe

The intertwining of charge, spin, and lattice degrees of freedom underlies the emergent properties of correlated materials. A recent prominent example is the kagome metal FeGe, which hosts coexisting charge density wave (CDW) and antiferromagnetic orders, accompanied by a lattice distortion associated with partial Ge-Ge dimerization. Using temperature-dependent high-resolution X-ray diffraction measurements, we observed a robust splitting of the lattice reflection into two coexisting peaks with distinct lattice constants at the CDW transition temperature TCDW, providing direct evidence for a first-order structural phase transition that is absent in samples with suppressed CDW order. Furthermore, the long-range CDW order was found to be only commensurate with lattice structures with the compressed out-of-plane lattice constant. The Landau free energy analysis shows that strong lattice-charge coupling is a key factor in stabilizing long-range CDW order. Our work clarifies the critical role of structural transformation in the CDW formation and opens opportunities for strain control of electronic phases in FeGe.

cond-mat.mtrl-sci↗

arXiv2026

DDNet: A Dual-Stream Graph Learning and Disentanglement Framework for Temporal Forgery Localization

The rapid evolution of AIGC technology enables misleading viewers by tampering mere small segments within a video, rendering video-level detection inaccurate and unpersuasive. Consequently, temporal forgery localization (TFL), which aims to precisely pinpoint tampered segments, becomes critical. However, existing methods are often constrained by \emph{local view}, failing to capture global anomalies. To address this, we propose a \underline{d}ual-stream graph learning and \underline{d}isentanglement framework for temporal forgery localization (DDNet). By coordinating a \emph{Temporal Distance Stream} for local artifacts and a \emph{Semantic Content Stream} for long-range connections, DDNet prevents global cues from being drowned out by local smoothness. Furthermore, we introduce Trace Disentanglement and Adaptation (TDA) to isolate generic forgery fingerprints, alongside Cross-Level Feature Embedding (CLFE) to construct a robust feature foundation via deep fusion of hierarchical features. Experiments on ForgeryNet and TVIL benchmarks demonstrate that our method outperforms state-of-the-art approaches by approximately 9\% in AP@0.95, with significant improvements in cross-domain robustness.

cs.CV↗

arXiv2026

Anti-reflection coatings for highly anisotropic materials in the mid infrared

We develop and optimize thin anti-reflection coatings (ARCs) for highly anisotropic materials in the mid infrared. Unlike conventional ARCs that assume nearly isotropic refractive indices, this work fully integrates the anisotropic nature of materials into the design process. We describe two designs of thin ARCs for highly anisotropic materials: a single form-birefringent layer, and a planar bilayer. We realized the planar bilayer ARC experimentally, demonstrating excellent mid-infrared anti-reflectance across over a broad range of angles for all polarizations.

physics.optics↗

arXiv2025

Crystal Growth of Chalcogenides and Oxy-Chalcogenides Using Chloride Exchange Reaction

Chalcogenides and oxy-chalcogenides, including complex chalcogenides and transition metal dichalcogenides, are emerging semiconductors with direct or indirect band gaps within the visible spectrum. These materials are being explored for various photonic and electronic applications, such as photodetectors, photovoltaics, and phase-change electronics. Understanding the fundamental properties of these materials is crucial for optimizing their functionalities. Therefore, the availability of large, high-quality single crystals of chalcogenides and oxy-chalcogenides is essential for a better comprehension of their structure and properties. In this study, we present a novel crystal growth method that utilizes the exchange reaction between BaS and ZrCl$_4$/ HfCl$_4$. By carefully controlling the stoichiometric ratio of the binary sulfide to the chloride, we can grow single crystals of several materials, such as ZrS$_2$, HfS$_2$, BaZrS$_3$, and ZrOS. This method results in large single crystals with a short reaction time of 24 to 48 hours. High-resolution thin film diffraction and single-crystal X-ray diffraction confirm the quality of the crystals produced through this exchange reaction. We also report the optical properties of these materials investigated using photoluminescence and Raman measurements. The chloride exchange reaction method paves the way for the synthesis of single crystals of chalcogenides and oxy-chalcogenide systems with a short reaction time but with low mosaicity and can be an alternative growth technique for single crystals of materials that are difficult to synthesize using conventional growth techniques.

cond-mat.mtrl-sci↗

arXiv2025

LiDARDustX: A LiDAR Dataset for Dusty Unstructured Road Environments

Autonomous driving datasets are essential for validating the progress of intelligent vehicle algorithms, which include localization, perception, and prediction. However, existing datasets are predominantly focused on structured urban environments, which limits the exploration of unstructured and specialized scenarios, particularly those characterized by significant dust levels. This paper introduces the LiDARDustX dataset, which is specifically designed for perception tasks under high-dust conditions, such as those encountered in mining areas. The LiDARDustX dataset consists of 30,000 LiDAR frames captured by six different LiDAR sensors, each accompanied by 3D bounding box annotations and point cloud semantic segmentation. Notably, over 80% of the dataset comprises dust-affected scenes. By utilizing this dataset, we have established a benchmark for evaluating the performance of state-of-the-art 3D detection and segmentation algorithms. Additionally, we have analyzed the impact of dust on perception accuracy and delved into the causes of these effects. The data and further information can be accessed at: https://github.com/vincentweikey/LiDARDustX.

cs.CV↗

arXiv2025

Towards Atomic-Scale Control over Structural Modulations in Quasi-1D Chalcogenides for Colossal Optical Anisotropy

Optically anisotropic materials are sought after for tailoring the polarization of light. Recently, colossal optical anisotropy was reported in a quasi-one-dimensional chalcogenide, Sr1.125TiS3. Compared to SrTiS3, the excess Sr in Sr1.125TiS3 leads to periodic structural modulations and introduces additional electrons that undergo charge ordering on select Ti atoms to form a highly polarizable cloud oriented along the c-axis, hence, resulting in the colossolal optical anisotropy. Here, further enhancement of the colossal optical anisotropy to 2.5 in Sr1.143TiS3 is reported through control over the periodicity of the atomic-scale modulations. The role of structural modulations in tuning the optical properties in a series of SrxTiS3 compounds has been investigated using DFT calculations. The structural modulations arise from various stacking sequences of face-sharing TiS6 octahedra and twist-distorted trigonal prisms, and are found to be thermodynamically stable for x larger than 1 but smaller than 1.5. As x increases, an indirect-to-direct band gap transition is predicted for x equal to and larger than 1.143 along with an increased occupancy of Ti-dz2 states. Together, these two factors result in a theoretically predicted maximum birefriengence of 2.5 for Sr1.143TiS3. Single crystals of Sr1.143TiS3 were grown using a molten-salt flux method. Atomic-scale observations using scanning transmission electron microscopy confirm the feasibility of synthesizing SrxTiS3 with varied modulation periodicities. Overall, these findings demonstrate compositonal tunability of optical properties in SrxTiS3 compounds, and potentially in other hexagonal perovskites having structural modulations.

cond-mat.mtrl-sci↗

arXiv2025

Colossal enhancement of spin transmission through magnon confinement in an antiferromagnet

Since Felix Bloch's introduction of the concept of spin waves in 1930, magnons (the quanta of spin waves) have been extensively studied in a range of materials for spintronics, particularly for non-volatile logic-in-memory devices. Controlling magnons in conventional antiferromagnets and harnessing them in practical applications, however, remains a challenge. In this letter, we demonstrate highly efficient magnon transport in an LaFeO$_3$/BiFeO$_3$/LaFeO$_3$ all-antiferromagnetic system which can be controlled electrically, making it highly desirable for energy-efficient computation. Leveraging spin-orbit-driven spin-charge transduction, we demonstrate that this material architecture permits magnon confinement in ultrathin antiferromagnets, enhancing the output voltage generated by magnon transport by several orders of magnitude, which provides a pathway to enable magnetoelectric memory and logic functionalities. Additionally, its non-volatility enables ultralow-power logic-in-memory processing, where magnonic devices can be efficiently reconfigured via electrically controlled magnon spin currents within magnetoelectric channels.

cond-mat.mtrl-sci↗

arXiv2025

Joint Modelling Histology and Molecular Markers for Cancer Classification

Cancers are characterized by remarkable heterogeneity and diverse prognosis. Accurate cancer classification is essential for patient stratification and clinical decision-making. Although digital pathology has been advancing cancer diagnosis and prognosis, the paradigm in cancer pathology has shifted from purely relying on histology features to incorporating molecular markers. There is an urgent need for digital pathology methods to meet the needs of the new paradigm. We introduce a novel digital pathology approach to jointly predict molecular markers and histology features and model their interactions for cancer classification. Firstly, to mitigate the challenge of cross-magnification information propagation, we propose a multi-scale disentangling module, enabling the extraction of multi-scale features from high-magnification (cellular-level) to low-magnification (tissue-level) whole slide images. Further, based on the multi-scale features, we propose an attention-based hierarchical multi-task multi-instance learning framework to simultaneously predict histology and molecular markers. Moreover, we propose a co-occurrence probability-based label correlation graph network to model the co-occurrence of molecular markers. Lastly, we design a cross-modal interaction module with the dynamic confidence constrain loss and a cross-modal gradient modulation strategy, to model the interactions of histology and molecular markers. Our experiments demonstrate that our method outperforms other state-of-the-art methods in classifying glioma, histology features and molecular markers. Our method promises to promote precise oncology with the potential to advance biomedical research and clinical applications. The code is available at https://github.com/LHY1007/M3C2

cs.CV↗

arXiv2024

Electrical contacts for high performance optoelectronic devices of BaZrS3 single crystals

Chalcogenide perovskites such as BaZrS3 are promising candidates for next generation optoelectronics such as photodetectors and solar cells. Compared to widely studied polycrystalline thin films, single crystals of BaZrS3 with minimal extended and point defects, are ideal platform to study the material's intrinsic transport properties and to make first-generation optoelectronic devices. However, the surface dielectrics formed on BaZrS3 single crystals due to sulfating or oxidation have led to significant challenges to achieving high quality electrical contacts, and hence, realizing the high-performance optoelectronic devices. Here, we report the development of electrical contact fabrication processes on BaZrS3 single crystals, where various processes were employed to address the surface dielectric issue. Moreover, with optimized electrical contacts fabricated through dry etching, high-performance BaZrS3 photoconductive devices with a low dark current of 0.1 nA at 10 V bias and a fast transient photoresponse with rise and decay time of <0.2 s were demonstrated.

cond-mat.mtrl-sci↗

arXiv2024

Strain-driven stabilization of a room-temperature chiral multiferroic with coupled ferroaxial and ferroelectric order

Noncollinear ferroic materials are sought after as testbeds to explore the intimate connections between topology and symmetry, which result in electronic, optical and magnetic functionalities not observed in collinear ferroic materials. For example, ferroaxial materials have ordered rotational structural distortions that break mirror symmetry and induce chirality. When ferroaxial order is coupled with ferroelectricity arising from a broken inversion symmetry, it offers the prospect of electric-field-control of the ferroaxial distortions and opens up new tunable functionalities. However, chiral multiferroics, especially ones stable at room temperature, are rare. We report the discovery of a strain-stabilized, room-temperature chiral multiferroic phase in single crystals of BaTiS$_3$, a quasi-one-dimensional (1D) hexagonal chalcogenide. Using first-principles calculations, we predict the stabilization of this multiferroic phase having $P6_3$ space group for biaxial tensile strains exceeding 1.5% applied on the basal ab-plane of the room temperature $P6_3cm$ phase of BaTiS$_3$. The chiral multiferroic phase is characterized by rotational distortions of select TiS$_6$ octahedra around the long $c$-axis and polar displacement of Ti atoms along the $c$-axis. We used an innovative approach using focused ion beam milling to make appropriately strained samples of BaTiS$_3$. The ferroaxial and ferroelectric distortions, and their domains in $P6_3$-BaTiS$_3$ were directly resolved using atomic resolution scanning transmission electron microscopy. Landau-based phenomenological modeling predicts a strong coupling between the ferroelectric and the ferroaxial order making $P6_3$-BaTiS$_3$ an attractive test bed for achieving electric-field control of chirality-related phenomena such as circular photo-galvanic current and the Rashba effect.

cond-mat.mtrl-sci↗

arXiv2024

Emergent Atomic Scale Polarisation Vortices in BaTiS3

Topological defects, such as vortices and skyrmions in magnetic and dipolar systems, can give rise to properties that are not observed in typical magnets and dielectrics. Here, we report the discovery of long-range ordered periodic dipole arrays of atomic-scale vortices and antivortices in the unconventional charge-density-wave (CDW) phase of BaTiS3, a quasi-1D chalcogenide. Synchrotron X-ray diffraction (XRD) reveals the presence of a multi-q ordering in BaTiS3 that confines vortex-vortex-antivortex polarisation triplets to the a-b plane with alternating handedness along the c-axis. The multi-q displacive distortions are characterised by three distinctive off-centre TiS6 configurations, whose ratios are independently confirmed by 47/49Ti solid-state nuclear magnetic resonance (SSNMR). Using first-principles calculations and phenomenological modelling, we show that the dipolar vortex unit cell in BaTiS3 arises from the coupling between multiple lattice instabilities arising from flat, soft phonon bands. This mechanism contrasts with classical dipolar textures in ferroelectric heterostructures that emerge from the competition between electrostatic and strain energies. The observation of dipolar vortices in BaTiS3 brings the ultimate scaling limit for real-space dipolar topological structures down to about a nanometre and unveils the intimate connection between crystal symmetry and real-space topology. Our work sets up zero-filling semiconducting materials with competing structural instabilities as a playground for realising and understanding quantum polarisation topologies.

cond-mat.mtrl-sci↗

arXiv2024

Bifunctional Noble Metal-free Ternary Chalcogenide Electrocatalysts for Overall Water Splitting

Hydrogen has been identified as a clean, zero carbon, sustainable, and promising energy source for the future, and electrochemical water splitting for hydrogen production is an emission-free, efficient energy conversion technology. A major limitation of this approach is the unavailability of efficient, abundant, inexpensive catalysts, which prompts the need for new catalytic materials. Here, we report the synthesis and electrocatalytic properties of a novel transition metal-based ternary chalcogenide family, LaMS$_3$ (M = Mn, Fe, Co, Ni). Powder X-ray diffraction confirms the phase purity of these materials, while composition analysis using energy dispersive spectroscopy (EDS) confirms the presence of the stoichiometric ratio of elements in these compounds. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) were used to study the chemical states on the surface and in bulk, respectively. These materials exhibit bifunctional catalytic activity towards the two half-reactions of the water-splitting process, with LaNiS$_3$ being the most active material for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The LaMS$_3$ compounds show long-term stability with negligible change in the overpotential at a constant current density of 10 mA cm$^{-2}$ over 18 hours of measurements. As compared to the corresponding ternary oxides, the LaMS$_3$ materials exhibit higher activity and significantly lower Tafel slopes. The ability to catalyze both half-reactions of water electrolysis makes these materials promising candidates for bifunctional catalysts and presents a new avenue to search for high-efficiency electrocatalysts for water splitting.

physics.chem-ph↗

arXiv2024

Molten flux growth of single crystals of quasi-1D hexagonal chalcogenide BaTiS3

BaTiS3, a quasi-1D complex chalcogenide, has gathered considerable scientific and technological interest due to its giant optical anisotropy and electronic phase transitions. However, the synthesis of high-quality BaTiS3 crystals, particularly those featuring crystal sizes of millimeters or larger, remains a challenge. Here, we investigate the growth of BaTiS3 crystals utilizing a molten salt flux of either potassium iodide, or a mixture of barium chloride and barium iodide. The crystals obtained through this method exhibit a substantial increase in volume compared to those synthesized via the chemical vapor transport method, while preserving their intrinsic optical and electronic properties. Our flux growth method provides a promising route towards the production of high-quality, large-scale single crystals of BaTiS3, which will greatly facilitate advanced characterizations of BaTiS3 and its practical applications that require large crystal dimensions. Additionally, our approach offers an alternative synthetic route for other emerging complex chalcogenides.

cond-mat.mtrl-sci↗

arXiv2024

Infrared Optical Anisotropy in Quasi-1D Hexagonal Chalcogenide BaTiSe3

Polarimetric infrared detection bolsters IR thermography by leveraging the polarization of light. Optical anisotropy, i.e., birefringence and dichroism, can be leveraged to achieve polarimetric detection. Recently, giant optical anisotropy was discovered in quasi-1D narrow-bandgap hexagonal perovskite sulfides, A1+xTiS3, specifically BaTiS3[1,2] and Sr9/8TiS3[3,4]. In these materials, the critical role of atomic-scale structure modulations[4,5] in the unconventional electrical[5,6], optical[7,8], and thermal[7,9] properties raises the broader question of other materials that belong to this family. To address this issue, for the first time, we synthesized high-quality single crystals of a largely unexplored member of the A1+xTiX3 (X = S, Se) family, BaTiSe3. Single-crystal X-ray diffraction determined the room-temperature structure with the P31c space group, which is a superstructure of the earlier reported[10] P63/mmc structure. The crystal structure of BaTiSe3 features antiparallel c-axis displacements similar to BaTiS3,[2] but is of lower symmetry. Polarization-resolved Raman and Fourier transform infrared (FTIR) spectroscopy were used to characterize the optical anisotropy of BaTiSe3, whose refractive index along the ordinary (perpendicular to c) and extraordinary (parallel to c) optical axes was quantitatively determined by combining ellipsometry studies with FTIR. With a giant birefringence {\Delta}n~0.9, BaTiSe3 emerges as a new candidate for miniaturized birefringent optics for mid-wave infrared to long-wave infrared imaging.

cond-mat.mtrl-sci↗

arXiv2023

Ruddlesden-Popper chalcogenides push the limit of mechanical stiffness and glass-like thermal conductivity in single crystals

Insulating materials featuring ultralow thermal conductivity for diverse applications also require robust mechanical properties. Conventional thinking, however, which correlates strong bonding with high atomic-vibration-mediated heat conduction, led to diverse weakly bonded materials that feature ultralow thermal conductivity and low elastic moduli. One must, therefore, search for strongly-bonded single crystals in which heat transport is impeded by other means. Here, we report intrinsic, glass-like, ultralow thermal conductivity and ultrahigh elastic-modulus/thermal-conductivity ratio in single-crystalline Ruddlesden-Popper Ban+1ZrnS3n+1, n = 2,3, which are derivatives of BaZrS3. Their key features are strong anharmonicity and intra-unit-cell rock-salt blocks. The latter produce strongly bonded intrinsic superlattices, impeding heat conduction by broadband reduction of phonon velocities and mean free paths and concomitant strong phonon localization. The present study initiates a paradigm of mechanically stiff phonon glasses.

cond-mat.mtrl-sci↗