Near-room-temperature spin caloritronics in a magnetized and defective zigzag MoS_2 nanoribbon

摘要

Using a tight-binding approach and first-principles calculations combined with the nonequilibrium Green's function method, the thermal spin transport in a zigzag molybdenum disulfide (MoS2nanoribbon in the proximity of a ferromagnetic insulator that induces a local exchange magnetic field in the center of the nanoribbon is investigated. It is found that a pure spin current and perfect spin Seebeck effect with zero charge current can be generated by applying a thermal gradient and local exchange magnetic field without a bias voltage near room temperature. Furthermore, it is shown that this nanoscale device can act as a spin Seebeck diode for the control of thermal and spin information in spin caloritronics applications. Finally, the impact of structural defects including edge and Stone-Wales defects on the spin figure of merit is studied. It is then shown that the spin figure of merit can be higher for a magnetized and defective MoS2nanoribbon. The results of this work facilitate deep understanding of the effects of structural defects on the thermoelectric properties of MoS2 nanoribbons and indicate their great potential for use in spin caloritronics devices for operation at room temperature.