Nonlinear optical Hall effect of few-layered NbSe2

Abstract

NbSe${}_2$ is one of metallic two-dimensional (2D) transition-metal dichalcogenide (TMDC) materials. Because of broken crystal inversion symmetry, large spin splitting is induced by Ising-type spin-orbit coupling in odd-number-layered NbSe${}_2$, but absent for even-number-layered NbSe${}_2$ with the inversion symmetry. In this paper, we numerically calculate nonlinear optical charge and spin Hall conductivities of few-layered NbSe${}_2$ based on an effective tight-binding model which includes $d_{z^2}$, $d_{x^2-y^2}$ and $d_{xy}$ orbitals of Nb atom. We show that the nonlinear optical Hall conductivity for second harmonic generation (SHG) process has nonvanishing value in odd-number-layered NbSe${}_2$. Also, we provide nonlinear optical selection rule in few-layered NbSe${}_2$ and their polarization dependences. In further, for even-number-layered case, the nonlinear optical Hall currents can be generated by applying electric fields which break inversion symmetry. We also discuss that the nonlinear optical Hall effect is expected to occur in TMDC materials in general. Thus, our results will serve to design potential opt-spintronics devices based on 2D materials to generate the spin Hall current by SHG.

16 pages, 8 figures

References in corpus (6)

• Two Dimensional Atomic Crystals
• Valley polarization in MoS2 monolayers by optical pumping
• Electrical Control of Second-Harmonic Generation in a WSe2 Monolayer Transistor
• Nonlinear optical selection rules of excitons in monolayer transition metal dichalcogenides
• Quasiparticle energy bands and Fermi surfaces of monolayer NbSe${}_2$
• Phase matched nonlinear optics via patterning layered materials

Cited by in corpus (1)

• Symmetry manipulation of nonlinear optical effect for metallic TMDC