Valley-related multiple Hall effect in monolayer VSi2P4

Abstract

2D materials with valley-related multiple Hall effect are both fundamentally intriguing and practically appealing to explore novel phenomena and applications, but have been largely overlooked up to date. Here, using first-principles calculations, we present that valley related multiple Hall effect can exist in singlelayer VSi2P4. We identify single-layer VSi2P4 as a ferromagnetic semiconductor with out-of-plane magnetization and valley physics. Arising from the joint effect of inversion symmetry breaking and time reversal symmetry breaking, the exotic spontaneous valley polarization occurs in single-layer VSi2P4, thus facilitating the observation of anomalous valley Hall effect. Moreover, under external strain, band inversion can occur at only one of the valleys of single-layer VSi2P4, enabling the long-sought valley-polarized quantum anomalous Hall effect, and meanwhile the anomalous valley Hall effect is well preserved.. Our work not only enriches the research on valley-related multiple Hall effect, but also opens a new avenue for exploring valley-polarized quantum anomalous Hall effect.

Conduction band-edge valley splitting in two-dimensional ferroelectric AgBiP2S6 by magnetic doping: towards electron valley-polarized transport

“…The carriers at the CBM are spin polarized and the degeneracy of the CBM at K and K 0 valleys is lied with an energy difference of about 171 meV due to the SOC effect. This intrinsic valley splitting in such a magnetic semiconductor is similar to the previous reports, such as Nb 3 I 8 , 65 NbSe 2 , 66 and LaBr 2 . 67 In Fig.…”

Intrinsic ferromagnetism and restrictive thermodynamic stability in MA$_2$N$_4$ and Janus VSiGeN$_4$ monolayers

“…For example, density functional theory (DFT) and Monte Carlo calculations suggested that monolayers VSi 2 N 4 and VSi 2 P 4 in the same structure as MoSi 2 N 4 have magnetic phase transition temperatures above room temperature, but they are XY magnets. 22,26 Nevertheless, VSi 2 P 4 monolayer in a different crystal structure is the only reported 2D magnet with an out-of-plane easy axis, but its predicted T c is merely about 90 K. 18 In this work, from the first-principles thermodynamic stability analysis (cf. supporting information S1) for all the nine 2D magnetic MA 2 Z 4 monolayers, we explain why they have not been synthesized so far and suggest possible routes to grow them.…”

Room-temperature spin valve effect in the TiCr2N4 monolayer

“…24 The magnetic properties of the VSi 2 N 4 monolayer can be effectively modulated by applying tensile biaxial strain or electron doping. The valley property, 25,26 topological feature, 27 and intrinsic piezoelectricity 28 were predicted for VSi 2 N 4 or VSi 2 P 4 monolayers. A bias-dependent spin filtering effect and the temperature-driven spin Seebeck effect were found in the VSi 2 X 4 (X = N, P, and As) monolayers, 22 which show potential applications in spintronics and thermoelectricity.…”