arXiv subjects

Shivam Rathod

Publications and source records attributed to Shivam Rathod.

3 recordsLinked to original sources

arXiv2026

Complex field-induced magnetic phases and anisotropic magnetotransport in off-stoichiometric CeCuBi2

We report a detailed study on the structural, angle-dependent magnetic and magnetotransport properties of highly anisotropic off-stoichiometric CeCuBi2 single crystals. Our results reveal CeCuBi2 as an anisotropic Kondo antiferromagnet exhibiting complex field-induced magnetic behavior and unusual magnetotransport properties. Magnetic susceptibility and specific heat measurements reveal antiferromagnetic (AFM) ordering below TN = 14 K with strong anisotropy and weak heavy-fermion behavior. Electrical transport measurements show highly anisotropic resistivity and a broad hump around 47 K, indicative of Kondo-driven heavy-fermion behavior. Magnetization measurements reveal multiple field-induced metamagnetic phases, while AC susceptibility measurements indicate slow spin dynamics and spin-glass-like behavior in intermediate field-induced magnetic states. Furthermore, we observe large and strongly anisotropic magneto transport responses, including room-temperature magnetoresistance of approximately 22% at 300 K and 9 T and butterfly-like anisotropic magnetoresistance with AMR values reaching approximately 10.9%. These results highlight a strong interplay among Kondo correlations, magnetic anisotropy, and field-tunable spin configurations, making CeCuBi2 a possible platform for exploring correlated and anisotropic quantum phenomena.

cond-mat.str-el↗

arXiv2026

Berry curvature induced giant anomalous and spin texture driven Hall responses in the layered kagome antiferromagnet GdTi3Bi4

In recent years, layered kagome magnets have emerged as promising platforms for Berry-curvature engineering and unconventional transport phenomena. Here, we present the single-crystal growth, magnetization, and electrical transport characterizations of the van der Waals-like layered antiferromagnet GdTi3Bi4. The system exhibits pronounced field-induced first-order phase transitions. Comprehensive frequency, temperature, and field-dependent ac susceptibility measurements, and Hall analysis, reveals the formation of a spin-cluster-like glassy magnetic phase attributed to noncollinear spin textures. Additionally, the system demonstrates a colossal anomalous Hall conductivity {\sigma}_xy^{A}~ 8.6(7)10^{3} Ohm-1 cm-1 at 2 K). Detailed scaling analyses reveal the coexistence of skew scattering and intrinsic Berry-curvature contributions to the anomalous Hall effect. First-principles calculations highlight flat-band near the Fermi level, with f-electrons of the Gd ion contributing large intrinsic Hall response. Thus, GdTi3Bi4 emerges as a rare layered kagome magnet, exhibiting Berry curvature-induced giant anomalous and spin texture-driven Hall responses, providing a versatile platform for exploring spin-texture physics and advancing low-dimensional spintronic functionalities.

cond-mat.mtrl-sci↗

arXiv2023

How to enhance anomalous Hall effects in magnetic Weyl semimetal Co$_3$Sn$_2$S$_2$?

Large spin-orbit coupling, kagome lattice, nontrivial topological band structure with inverted bands anti-crossings, and Weyl nodes are essential ingredients, ideally required to obtain maximal anomalous Hall effect (AHE) are simultaneously present in Co$_3$Sn$_2$S$_2$. It is a leading platform to show large intrinsic anomalous Hall conductivity (AHC) and giant anomalous Hall angle (AHA) simultaneously at low fields. The giant AHE in Co$_3$Sn$_2$S$_2$ is robust against small-scale doping-related chemical potential changes. In this work, we unveil a selective and co-chemical doping route to maximize AHEs in Co$_3$Sn$_2$S$_2$. To begin with, in Co$_3$Sn$_{2-x}$In$_x$S$_2$, we brought the chemical potential at the hotspot of Berry curvature along with a maximum of asymmetric impurity scattering in high mobility region. As a result at x=0.05, we found a significant enhancement of AHA (95%) and AHC (190%) from the synergistic enhancement of extrinsic and intrinsic mechanisms from modified Berry curvature of gaped nodal lines. Later, with anticipation of further improvements in AHE, we grew hole-co-doped Co$_{3-y}$Fe$_y$Sn$_{2-x}$In$_x$S$_2$ crystals, where we found rather a suppression of AHEs. The role of dopants in giving extrinsic effects or band broadening can be better understood when chemical potential does not change after doping. By simultaneous and equal co-doping with electrons and holes in Co$_{3-y-z}$Fe$_y$Ni$_z$Sn$_2$S$_2$, we kept the chemical potential unchanged. Henceforth, we found a significant enhancement in intrinsic AHC $\sim$116% due to the disorder broadenings in kagome bands

cond-mat.mtrl-sci↗