Spin transport properties in Dirac spin gapless semiconductors Cr2X3 with high Curie temperature and large magnetic anisotropic energy

Abstract

2D honeycomb-Kagome (HK) lattices have attracted extensive attention in recent years due to the peculiar electronic and magnetic properties such as the Dirac band, the half-metallicity, and the high Curie temperature. In this Letter, we theoretically investigate the spin transport properties of a recently proposed 2D Dirac spin gapless semiconductor (also known as a Dirac half-metal with zero energy gap in one spin channel) of the Cr2S3 monolayer with the HK lattice. The excellent spin filtering effect and negative differential resistance effect are found at a bias voltage, and interestingly, a temperature difference can also drive the spin filtering effect. These peculiar transport properties can be understood from the Dirac spin gapless semiconductivity and the spin-dependent transmission spectrum. In addition, we predict that, similar to Cr2S3 and Cr2Se3, 2D Cr2Te3 is also a Dirac spin gapless semiconductor with the above room-temperature Curie temperature and a large magneto-crystalline anisotropic energy (MAE). Under a tensile biaxial strain, the MAE can be greatly increased, and the easy magnetization axis is still along the in-plane. All these results are achieved by the first-principles combined with nonequilibrium Green's function method. The present work will stimulate theoretical and experimental studies on spintronic devices and spin caloritronic devices based on more 2D Dirac HK lattices.