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Yunxing Li

Publications and source records attributed to Yunxing Li.

3 recordsLinked to original sources

Magnetotransport evolution and nonlinear Hall effect in altermagnetic MnTe

Hexagonal MnTe is a prototypical semiconducting altermagnet whose properties are heavily influenced by intrinsic disorder, yet how the resulting diverse transport regimes shape its magnetotransport behavior remains to be clarified alongside the role of relativistic spin-orbit coupling (SOC). Here, we present a systematic study of the anisotropic magnetoresistance (AMR), planar Hall effect (PHE), and nonlinear transport in MnTe bulk single crystals. Below the N\'eel temperature (TN ~ 304 K), the emergence of high-order harmonics in AMR and PHE within the high-temperature metallic regime reveals the interplay of magnetic order, crystalline symmetry, and SOC. At relatively lower temperatures, the disappearance of higher-order symmetries coincides with a transport crossover into the hopping conduction regime, suggesting that carrier localization diminishes the transport sensitivity to the Fermi-surface topology. In addition, we detect distinct second-order nonlinear Hall signals, providing evidence for a macroscopic inversion-asymmetric response in altermagnetic MnTe. Extending the investigations into the localized regime provides key insights into the subtle role of disorder and SOC in macroscopic charge transport. Our work thus underscores the necessity of exploring magnetotransport across diverse conducting regimes to comprehensively understand altermagnetic properties.

cond-mat.mtrl-sci

Evolution from Landau Quantization to Discrete Scale Invariance Revealed by Quantum Oscillations in Topological Materials

Dirac materials have been a unique solid state platform for exploring relativistic quantum phenomena including supercritical atomic collapse, which leads to emergent discrete scale symmetry and logperiodic quantum oscillations. In the relativistic regime, the fundamental effect in quantum electrodynamics, vacuum polarization, can further modulate the atomic collapselike state by screening bare charges but is rarely harnessed in condensed matter system. Here, we report a continuous progression from low field Shubnikov de Haas oscillations to high field log periodic oscillations in the Dirac material HfTe5, with both phenomena modulated by Fermi surface anisotropy. This maps the transition from single particle Landau levels to an interaction-driven, discrete scale invariant energy spectrum of quasi-bound states. Crucially, our findings suggest vacuum polarization provides a compelling mechanism for renormalizing the effective impurity charge, quantitatively explaining the carrier-density dependent scale factor. By revealing the intricate interplay between Landau quantization, many body electronic screening, and scale-symmetry breaking, our results establish Dirac solids as a controllable platform for exploring relativistic vacuum effects and emergent novel symmetry.

cond-mat.mtrl-sci

Exotic Surface Stripe Orders in Correlated Kagome Metal CsCr3Sb5

The newly discovered kagome superconductor CsCr3Sb5 exhibits distinct features with flat bands and unique magnetism, providing a compelling platform for exploring novel quantum states of correlated electron systems. Emergent charge order in this material is a key for understanding unconventional superconductivity, but it remains unexplored at the atomic scale and the underlying physics is elusive. Here, we identify and unreported stripe orders on the surface which are distinct from the bulk and investigate the underlying bulk electronic properties using a combination of scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations. Specifically, a mixture of 2a0 * a0 and 3a0 * a0 stripe order is found on Cs-terminated surface while 4a0 * root3a0 stripe order is found on the Sb-terminated surface. The electronic spectra exhibit strongly correlated features resembling that of high temperature superconductors, with kagome flat bands lying about 330 meV above EF, suggesting that the electron correlations arise from Coulomb interactions and Hund's coupling. Moreover, a distinct electron-boson coupling mode is observed at approximately 100 meV. These findings provide new insights into the interplay between surface and bulk charge orders in this strongly correlated kagome system.

cond-mat.str-el