Nonvolatile electrical control of spin polarization in the 2D bipolar magnetic semiconductor VSeF

Nonvolatile electrical control of spin polarization in two-dimensional (2D) magnetic semiconductors is greatly appealing toward future low-dissipation spintronic nanodevices. Here, we report a 2D material VSeF, which is an intrinsic bipolar magnetic semiconductor (BMS) featured with opposite spin-polarized valence and conduction band edges. We then propose a general nonvolatile strategy to manipulate both spin-polarized orientations in BMS materials by introducing a ferroelectric gate with proper band alignment. The spin-up/spin-down polarization of VSeF is successfully controlled by the electric dipole of ferroelectric bilayer Al2Se3, verifying the feasibility of the design strategy. The interfacial doping effect from ferroelectric gate also plays a role in enhancing the Curie temperature of the VSeF layer. Two types of spin field effect transistors, namely multiferroic memory and spin filter, are further achieved in VSeF/Al2Se3 and VSeF/Al2Se3/Al2Se3 multiferroic heterostructures, respectively. This work will stimulate the application of 2D BMS materials in future spintronic nanodevices.

Automated summary

This study reports a 2D material VSeF with opposite spin-polarized valence and conduction band edges, and proposes a general nonvolatile strategy to control the spin polarizations in BMS materials by introducing a ferroelectric gate. The electric dipole of ferroelectric bilayer Al2Se3 successfully controls the spin-up/spin-down polarization of VSeF, and the interfacial doping effect enhances its Curie temperature. Two types of spin field effect transistors, multiferroic memory and spin filter, are achieved in VSeF/Al2Se3 and VSeF/Al2Se3/Al2Se3 multiferroic heterostructures. This work will promote the application of 2D BMS materials in future spintronic nanodevices.