arXiv subjects

Trisha Musall

Publications and source records attributed to Trisha Musall.

3 recordsLinked to original sources

arXiv2026

Experimental investigation of altermagnetic order in Cr-doped FeSb2

Altermagnets are a class of materials with compensated magnetic moments, in which spin sublattices are related by specific rotational symmetries other than inversion or translation. This allows time-reversal symmetry to be broken without a net magnetization. Cr-doped FeSb2 has been theoretically proposed as a candidate d-wave altermagnetic system, yet its magnetic ground state has remained unresolved. Here, we synthesize single crystals of Fe1-xCrxSb2 and investigate their electrical transport and magnetic properties, with a focus on Fe0.85Cr0.15Sb2. Magnetization measurements suggest spin-compensated ordering below ~3.5 K, where magnetic moments align along the crystallographic b-direction. Transport measurements reveal a crossover from large positive to negative magnetoresistance, while an anomalous Hall response emerges below 5 K, indicating time-reversal symmetry breaking. Muon spin relaxation measurements confirm that the magnetic ordering below 3.5 K is bulk in nature. The absence of coherent oscillations in zero-field {\mu}SR spectra and of magnetic Bragg intensity in single-crystal neutron diffraction establishes that the magnetically ordered state is short-range or disordered, rather than collinear altermagnetic order. These results demonstrate that Cr-doping alone breaks time-reversal symmetry without stabilizing long-range altermagnetic order in FeSb2.

cond-mat.mtrl-sci↗

arXiv2025

Strain-tunability of the multipolar Berry curvature in altermagnet MnTe

The anomalous Hall effect describes the generation of a transverse voltage by a longitudinal current even in the absence of an external magnetic field. While typically observed in ferromagnets, it has also been predicted to arise in altermagnets, materials characterized by rotational symmetries that enable broken time reversal symmetry despite compensated collinear magnetic ordering. These symmetries enforce band (anti)crossings that can generate significant contributions to the Berry curvature that drives the anomalous Hall effect. This Berry curvature is predicted to exhibit a characteristic multipolar order, resulting in a symmetry-enforced distribution at or near net compensation which is highly sensitive to perturbations that distort this balance. However, exploring the predicted multipolar Berry curvature of altermagnets and its reversible manipulation remains challenging. Here, we demonstrate evidence for the multipolar nature of the altermagnetic Berry curvature in MnTe by tuning the anomalous Hall effect via uniaxial stress. Upon straining, the magnitude of the anomalous Hall conductivity changes and, at a critical strain of 0.14%, the sign is reversed. Symmetry analysis and density functional theory calculations reveal that this tunability is a direct consequence of the altermagnetic multipolar Berry curvature. Our results provide insight into the role of crystal and magnetic symmetries in the realization of higher-order Berry curvature distributions and their unique tunability.

cond-mat.mtrl-sci↗

arXiv2023

Evidence of Indium impurity band in superconducting (Sn,In)Te thin films

Sn1-xInxTe has been synthesized and studied recently as a candidate topological superconductor. Its superconducting critical temperature increases with Indium concentration. However, the role of Indium in altering the normal state band structure and generating superconductivity is not well-understood. Here, we explore this question in Sn1-xInxTe (0<x<0.3) thin films, characterized by magneto-transport, infrared transmission and photoemission spectroscopy measurement. We show that Indium is forming an impurity band below the valence band edge which pins the Fermi energy and effectively generates electron doping. An enhanced density-of-states due to this impurity band leads to the enhancement of superconducting transition temperature measured in multiple previous studies. The existence of the In impurity band and the role of In as a resonant impurity should be more carefully considered when discussing the topological nature of Sn1-xInxTe.

cond-mat.supr-con↗