arXiv subjects

Bhautik R Dhori

Publications and source records attributed to Bhautik R Dhori.

2 recordsLinked to original sources

arXiv2026

Interplay of Altermagnetism and Coupled Quasi-Altermagnetic states in Sliding Two-dimensional Square Lattice

The emergence of non-relativistic spin splitting (NRSS) in altermagnetic systems has introduced a new paradigm in antiferromagnets with vanishing net magnetization. Although sliding-induced valley-polarized phases have recently been demonstrated in two-dimensional altermagnets, the observed valley-polarized state represents only a partial manifestation of altermagnetism, and a comprehensive classification based on spinsplitting characteristics remains lacking. Here, using first-principles calculations, general stacking theory, and spin-Laue symmetry analysis, we propose a coupled quasialtermagnetic state representing a distinct subclass of altermagnetism, in which reversible type-IV NRSS is controlled through interlayer sliding. Accordingly, the sliding-induced phases are classified into two categories: altermagnetic and quasi-altermagnetic states. We establish a direct correspondence between reciprocal-space spin splitting and real-space switching between the two quasi-altermagnetic states. Importantly, the spin-polarized bands in these states remain spin split at Γ point even in the absence of spin-orbit coupling (SOC), distinguishing them within the proposed classification framework. To demonstrate the interplay between altermagnetic and quasi-altermagnetic states, we investigate the two-dimensional Lieb-lattice material Mn2WS4 and its Janus derivative Mn2WS2Se2, analysing how changes in the local environment influence the different magnetic phases. Importantly, the underlying mechanism is broadly applicable to a wide class of twodimensional square-lattice systems. We further investigate the effects of SOC, focusing on spin texture and transport signatures in coupled quasi-altermagnetic states.

cond-mat.mtrl-sci↗

arXiv2023

Non-trivial topological phases in transition metal rich half-Heusler Oxides

Topological Insulators with gapless surface states and insulating bulk in non-centrosymmetric cubic systems have been extensively explored following the discovery of two-dimensional quantum spin hall effect in zincblende HgTe. In such systems the negative band inversion strength E$_{BIS}$ ($=$ E$_{Γ_6} -$ E$_{Γ_8} <$ 0) governs the robustness of the non-trivial topological states at ambient conditions. Hence, realizing large negative values of E$_{BIS}$ has been a guiding motivation of several investigations reported in literature. Here, we present a material design approach which can be employed to realize large negative values of E$_{BIS}$ in cubic materials such as half-Heusler (HH) oxides with 18 valence electron configurations. We explore 27 HH oxides of the form ABO (A = Li, K, Rb; B = Cu, Ag, Au) in $α$-, $β$-, and $γ$-phase (by placing transition metal atom at different Wyckoff positions) for their non-trivial topological phase. Off these three phases, we found that, the $α$-phase of nine HH oxides (wherein the transition metal atoms occupy 4a Wyckoff positions in the crystal structure) is the most promising with non-trivial topological phase which is governed by the mass-darwin relativistic effects enhancing E$_{BIS}$. Whereas the other phases were found to be either trivial semiconductors or semimetals or metals and most of them being dynamically unstable. We focus on RbAuO in $α$-phase with E$_{BIS}$ of $-$ 1.29 eV and the effect of strain fields on the topological surface states of this compound. We conclude that the $α$-phase of HH oxide presented here can be synthesized experimentally for diverse room temperature applications in spintronics and nanoelectronics.

cond-mat.mtrl-sci↗