arXiv subjects

S. K. Behera

Publications and source records attributed to S. K. Behera.

3 recordsLinked to original sources

arXiv2026

Lattice-Driven Electronic Structure Reconstruction in the Commensurate CDW Phase of 1T-Ta$S_2$

We investigate the structural and electronic reconstruction associated with the commensurate charge-density-wave (CCDW) phase in bulk and monolayer 1T-TaS2 using density functional theory (DFT) and Wannier-based tight-binding modeling. Structural relaxation of a sqrt(13) x sqrt(13) supercell leads spontaneously to the formation of the Star-of-David (SoD) distortion, consistent with phonon softening of the undistorted phase. We focus on establishing a direct connection between real-space lattice distortion and momentum-space electronic reconstruction. Using Wannier interpolation, we demonstrate how the CCDW-induced Brillouin zone reduction leads to band folding, narrowing of Ta 5d bands, and reconstruction of the Fermi surface. Our analysis shows that features often interpreted as Fermi surface nesting emerge naturally from band folding associated with lattice distortion. We compare our calculated electronic structure with previously reported angle-resolved photoemission spectroscopy (ARPES) results at a qualitative level. While we do not explicitly compute electronic susceptibility or electron-phonon coupling matrix elements, the results provide a consistent microscopic framework linking lattice instability and electronic structure reconstruction in 1T-TaS2.

cond-mat.mes-hall↗

arXiv2025

Ferromagnetic CrBr$_3$-Induced Graphene Spintronics

Our proposed spin valve prototype showcases a sophisticated design featuring a two-dimensional graphene bilayer positioned between layers of ${CrBr}_3$ ferromagnetic insulators. In this model, proximity coupling plays a pivotal role, influencing the magnetization orientations of the graphene layers and significantly impacting the \textit{in-plane} conductivity of the ${CrBr}_3$ layers. In this present work, we position the graphene bilayer between two layers of the ferromagnetic insulator ${CrBr}_3$ to establish this configuration. Using density functional theory, we conduct detailed computations to analyze the electronic structure of this sandwiched system. Our findings reveal a notable finite gap at specific \textit{k}-points, particularly evident in the antiparallel configuration of the magnetizations. This finding represents a significant advancement in spintronics, underscoring the potential of our spin valve prototype to drive innovation in electronic device technologies.

cond-mat.mes-hall↗

arXiv2024

Interfacial Dynamics and Catalytic Behavior of Single Ni Atom Site

Single-atom catalysts (SACs) have garnered significant interest due to their ability to reduce metal particles to the atomic scale, enabling finely tunable local environments and enhanced catalytic properties in terms of reactivity and selectivity. Despite this potential, their application has largely been confined to small-molecule transformations as metal-catalyzed reaction. In this study, we present a diverse single-atom nickel (Ni) catalyst established via a nanoporous carbon (NPC) supported practice. This catalyst represents a breakthrough by achieving the bond formation between carbon and nitrogen and interfacial dynamics in the SAC. The present first principle-based density functional simulations establish the reaction dynamics and catalytic behaviour of such SAC. This dynamic nature comprises an exclusive nitrogen intercalated site showing excellent base effects. This base quickly tunes the interfacial atmosphere, enabling dynamic movement of adatoms into the NPC species, significantly changing the reaction path in Ni SACs due to superior steric effects. The research demonstrates that SACs can extend the capabilities of catalytic systems to include a wider range of complex reactions, offering substantial promise for the development of new, efficient synthetic methods for creating value-added molecular products.

cond-mat.mes-hall↗