High-Efficiency spin-Seebeck Diode in an ${\alpha }^{\prime }$-Borophene FM/Normal/FM Nanoribbon Junction

Abstract

The ${\alpha }^{\prime }$-borophene nanoribbon (${\alpha }^{\prime }$-BNR), due to its incredible properties such as high stability and great mobility of carriers, demonstrates high efficiency in thermoelectric devices. We show that these properties enable us to produce a pure spin current by applying a temperature gradient with lower energy consumption in a ferromagnetic/normal/ferromagnetic (FM/Normal/FM) junction. Spin-dependent thermoelectric properties and spin-Seebeck are studied in this junction using the tight-binding (TB) formalism in combination with the non-equilibrium Green's function method (NEGF). The pure spin current due to the breaking of the electron-hole symmetry is induced in the system so that it can act as a spin-Seebeck diode. Moreover, the negative differential spin-Seebeck effect can be observed in the system. Finally, we show that, under the same conditions, the ${\alpha }^{\prime }$-BNR has a much higher power factor compared to that of graphene and silicene, which is due to the high asymmetry between the electrons and holes in the ${\alpha }^{\prime }$-BNR. The exceptional features of ${\alpha }^{\prime }$-BNR make it a very suitable choice for thermoelectric devices.

18 pages, 9 figures