arXiv subjects

Avdhesh K. Sharma

Publications and source records attributed to Avdhesh K. Sharma.

2 recordsLinked to original sources

arXiv2026

Anisotropic anomalous Hall effect in distorted kagome GdTi3Bi4

Topological kagome magnets offer a rich landscape for exploring the intricate interplay of quantum interactions among geometry, topology, spin, and correlation. GdTi3Bi4 crystallizes in layered Ti based kagome nets intertwined with zigzag Gd chains along the a axis and orders antiferromagnetically below 15 K. Here, we present the temperature and field dependent electrical transport of GdTi3Bi4 in different directions. The material exhibits anomalous Hall conductivity (AHC) of 410 S cm-1 at 2 K for B parallel c and it is completely absent for B parallel a, despite the similar magnetization observed in both orientations. This behavior is quite contradictory, as anomalous Hall effect (AHE) typically scales with the magnetization. Through first principles calculations, it is demonstrated that in the presence of time reversal symmetry broken by the Gd 4f sublattice and spin orbit coupling, the magnetization direction controls the orbital mixing in the Ti t2g bands, relocating Berry curvature hot spots and producing the observed orientation selective AHC. The results establish GdTi3Bi4 as platform for investigating new avenues of AHE, such as directional AHE, and thus shed new light on the intricate coupling between magnetic and electronic structures, paving the way for exploring novel quantum phenomena.

cond-mat.mtrl-sci↗

arXiv2025

Topological quantum materials: kagome, chiral, and square-net frameworks

Topological quantum materials have emerged as a frontier in condensed matter physics as well as in materials science, with intriguing electronic states that are robust to perturbations. Among the diverse structural motifs, kagome, chiral, and square-net structures offer a wide range of topological phases and physical phenomena. These include Dirac and Weyl fermions, nodal-line semimetals, flat bands, van Hove singularities, charge density waves, superconductivity, nontrivial Berry phase, nonlinear electrical and thermal transports. This review explores the distinct roles of geometry, symmetry, spin-orbit coupling, and electron correlations in these three classes of materials. It also highlights how their crystallographic features give rise to unique electronic band structures, topologically protected states and different physical properties, which require high-quality-single crystals. The present discussion comprises recent experimental discoveries and identification of the synthesis routes of key materials within each framework. Finally, the review outlines the current challenges and future directions in the design and exploration of topological quantum materials.

cond-mat.mtrl-sci↗