arXiv subjects

Banik Rai

Publications and source records attributed to Banik Rai.

4 recordsLinked to original sources

arXiv2025

Cusplike feature in Hall resistivity of a uniaxial ferromagnet in nonorthogonal Hall geometry

Recent magnetotransport studies on uniaxial ferromagnets have reported a cusplike feature in Hall resistivity when the magnetic field is tilted away from the conventional orthogonal direction of the Hall measurement. This feature has often been attributed to the topological Hall effect arising from a non-coplanar spin structure. In this article, we have studied the uniaxial ferromagnet SmMn$_2$Ge$_2$ to demonstrate that this feature is rather a consequence of the nonorthogonal geometry of the Hall measurement and is expected to appear whenever the magnetic field is applied away from the easy axis of magnetization, nonorthogonal to the sample plane. The Hall resistivity, exhibiting this feature, scales with the orthogonal component of the magnetization, indicating that the observed feature is simply a manifestation of the anomalous Hall effect. We explain the origin of this feature based on the evolution of ferromagnetic domains under a nonorthogonal external magnetic field.

cond-mat.mes-hall↗

arXiv2025

Direction-Dependent Conduction Polarity in Altermagnetic CrSb

CrSb has recently gained immense attention as an altermagnetic candidate. This work reports on the experimental observation of direction-dependent conduction polarity (DDCP) in altermagnetic CrSb through Hall and Seebeck thermopower measurements. Conduction is dominated by holes along the c-axis and by electrons in the ab-plane of the hexagonal crystal of CrSb. Density functional theory (DFT) calculations indicate that DDCP in CrSb arises from a multicarrier mechanism, where electrons and holes living in distinct bands dominate conduction along different crystallographic directions. Furthermore, DFT predicts that DDCP exists within a narrow energy window near the Fermi level and is sensitive to small doping levels. This prediction is experimentally validated by the loss of DDCP in hole-doped Cr$_{0.98}$V$_{0.02}$Sb. These findings highlight the potential for tunable electronic behavior in CrSb, offering promising avenues for applications in devices that require both p-type and n-type functionalities within a single material.

cond-mat.mtrl-sci↗

arXiv2024

Peculiar magnetic and magneto-transport properties in a non-centrosymmetric self-intercalated van der Waals ferromagnet Cr5Te8

Trigonal Cr$_5$Te$_8$, a self-intercalated van der Waals ferromagnet with an out-of-plane magnetic anisotropy, has long been known to crystallize in a centrosymmetric structure. However, optical second harmonic generation experiments, together with comprehensive structural analysis, indicate that this compound rather adopts a non-centrosymmetric structure. Lorentz transmission electron microscopy reveals the presence of N\'eel-type skyrmions, consistent with its non-centrosymmetric structure. A large anomalous Hall conductivity of 102 ohm$^{-1}$cm$^{-1}$ at low temperature stems from intrinsic origin, which is larger than any previously reported values in the bulk Cr-Te system. Notably, spontaneous topological Hall resistivity arising from the skyrmionic phase has been observed. Our findings not only elucidate the unique magnetic and magneto-transport properties of non-centrosymmetric trigonal Cr$_5$Te$_8$, but also open new avenues for investigating the effects of broken inversion symmetry on material properties and their potential applications.

cond-mat.mtrl-sci↗

arXiv2024

Tuning intrinsic anomalous Hall effect from large to zero in two ferromagnetic states of SmMn2Ge2

The intrinsic anomalous Hall conductivity (AHC) in a ferromagnetic metal is completely determined by its band structure. Since the spin orientation direction is an important band-structure tuning parameter, it is highly desirable to study the anomalous Hall effect in a system with multiple spin reorientation transitions. We study a layered tetragonal room temperature ferromagnet SmMn2Ge2, which gives us the opportunity to measure magnetotransport properties where the long c-axis and the short a-axis can both be magnetically easy axes depending on the temperature range we choose. We show a moderately large fully intrinsic AHC up to room temperature when the crystal is magnetized along the c-axis. Interestingly, the AHC can be tuned to completely extrinsic with extremely large values when the crystal is magnetized along the a-axis, regardless of whether the a-axis is magnetically easy or hard axis. First-principles calculations show that nodal line states originate from Mn-d orbitals just below the Fermi energy (EF) in the electronic band structure when the spins are oriented along the c-axis. Intrinsic AHC originates from the Berry curvature effect of the gapped nodal lines in the presence of spin-orbit coupling. AHC almost disappears when the spins are aligned along the a-axis because the nodal line states shift above EF and become unoccupied. Since the AHC can be tuned from fully extrinsic to intrinsic even at 300 K, SmMn2Ge2 becomes a potential candidate for room-temperature spintronics applications.

cond-mat.mtrl-sci↗