自旋半导体纳米热电材料器件的高自旋极化电流

High Spin-polarization Currents in Spin-semiconducting Nanoscale Thermoelectric Material Devices

借助第一性原理设计了一种可以产生高自旋极化电流的自旋热电装置.该装置是由有源极(B掺杂后的石墨烯纳米带)、漏极(石墨烯纳米带)以及中间区域(碳原子链)构成.对比未掺杂情况,自旋向上的电流在高温区域可以提高100倍,同时自旋极化率可增强至接近1.而且自旋流在高温区域可以大于电荷流,其主要原因归结于掺杂后该装置表现为自旋半导体性质.

Exploiting high spin-polarization device is one of the major objectives in the field of spintronics. Inthis paper, a thermospin device is designed to generate the high spin-polarization currents based on thefirst-principles method. The device consists of the source electrode （B-doped graphene nanoribbon）, the drainelectrode （graphene nanoribbon）, and the central scattering region （the carbon atomic chain）. In contrast to theundoped case, the spin-up current induced by the temperature difference can be enhanced by 100 times in thehigh temperature region, and meanwhile the current spin-polarization can reach 1. Moreover, the spin current islarger than the charge current in the high-temperature region, which is ascribed to the spin-semiconductingproperty of the device after the B doping.