Correlation-driven topological and valley states in monolayer VSi${}_2$P${}_4$

Abstract

Electronic correlations could have significant impact on the material properties. They are typically pronounced for localized orbitals and enhanced in low-dimensional systems, so two-dimensional (2D) transition metal compounds could be a good platform to study their effects. Recently, a new class of 2D transition metal compounds, the MoSi${}_2$N${}_4$-family materials, have been discovered, and some of them exhibit intrinsic magnetism. Here, taking monolayer VSi${}_2$P${}_4$ as an example from the family, we investigate the impact of correlation effects on its physical properties, based on the first-principles calculations. We find that different correlation strength can drive the system into a variety of interesting ground states, with rich magnetic, topological and valley features. With increasing correlation strength, while the system favors a ferromagnetic semiconductor state for most cases, the magnetic anisotropy and the band gap type undergo multiple transitions, and in the process, the band edges can form single, two or three valleys for electrons or holes. Remarkably, there is a quantum anomalous Hall (QAH) insulator phase, which has a unit Chern number. The boundary of the QAH phase correspond to the half-valley semimetal state with fully valley polarized bulk carriers. We further show that for phases with the out-of-plane magnetic anisotropy, the interplay between spin-orbit coupling and orbital character of valleys enable an intrinsic valley polarization for electrons but not for holes. This electron valley polarization can be switched by reversing the magnetization direction, providing a new route of magnetic control of valleytronics. Our result sheds light on the possible role of correlation effects in the 2D transition metal compounds, and it will open new perspectives for spintronic, valleytronic and topological nanoelectronic applications based on these materials.

8 pages, 8 figures

References in corpus (14)

• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe
• Exceptional piezoelectricity, high thermal conductivity and stiffness and promising photocatalysis in two-dimensional MoSi2N4 family confirmed by first-principles
• Structure-driven intercalated architecture of septuple-atomic-layer $M{A}_2{Z}_4$ family with diverse properties from semiconductor to topological insulator to Ising superconductor
• Valley-dependent properties of monolayer MoSi${}_2$N${}_4$, WSi${}_2$N${}_4$ and MoSi${}_2$As${}_4$
• Valley pseudospin in monolayer MoSi2N4 and MoSi2As4
• Strain-induced semiconductor to metal transition in MA2Z4 bilayers
• Semiconductor-to-metal transition in bilayer MoSi${}_2$N${}_4$ and WSi${}_2$N${}_4$ with strain and electric field
• Cooperative Effect of Electron Correlation and Spin-Orbit Coupling on the Electronic and Magnetic Properties of Ba2NaOsO6
• Coexistence of intrinsic piezoelectricity and ferromagnetism induced by small biaxial strain in septuple-atomic-layer $\mathrm{VS}{\mathrm{i}}_2{\mathrm{P}}_4$
• Correlation-driven eightfold magnetic anisotropy in a two-dimensional oxide monolayer
• Valley-polarized quantum anomalous Hall phase and disorder induced valley-filtered chiral edge channels
• Interaction-induced quantum anomalous Hall phase in (111) bilayer of LaCoO${}_3$
• Designing Efficient Metal Contacts to Two-Dimensional Semiconductors MoSi${}_2$N${}_4$ and WSi${}_2$N${}_4$ Monolayers

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