Ding Guangqian, Hu Yonglan, Li Dengfeng, Wang Xiaotian, Qin Dan
School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
J Adv Res. 2020 May 17;24:391-396. doi: 10.1016/j.jare.2020.05.006. eCollection 2020 Jul.
Bipolar magnetic semiconductors (BMSs) are a new member of spintornic materials. In BMSs, one can obtain 100% spin-polarized currents by means of the gate voltage. However, most of previous studies focused on their applications in spintronics instead of spin caloritronics. Herein, we show that BMS is an intrinsic model for spin Seebeck effect (SSE). Without any gate voltage and electric field, currents with opposite spin orientation are generated and flow in opposite directions with almost equal magnitude when simply applying a temperature bias. This is also due to the special electronic structure of BMS where the conduction and valence bands near the Fermi level belong to opposite spin orientation. Based on density function theory and non-equilibrium Green's function methods, we confirm the thermal-induced SSE in BMS using a case of magnetic MoS nanotube. The magnitude of spin current in zigzag tube is almost four times higher than that in armchair tube. BMS is promising candidates for spin caloritronic applications.
双极磁半导体（BMSs）是自旋电子材料的新成员。在双极磁半导体中，可以通过栅极电压获得100%的自旋极化电流。然而，之前的大多数研究都集中在它们在自旋电子学中的应用，而非自旋热电子学。在此，我们表明双极磁半导体是自旋塞贝克效应（SSE）的一个本征模型。在不施加任何栅极电压和电场的情况下，当仅施加温度偏置时，会产生具有相反自旋取向的电流，并且它们以几乎相等的大小沿相反方向流动。这也是由于双极磁半导体的特殊电子结构，其中费米能级附近的导带和价带属于相反的自旋取向。基于密度泛函理论和非平衡格林函数方法，我们以磁性MoS纳米管为例证实了双极磁半导体中的热致自旋塞贝克效应。锯齿形纳米管中的自旋电流大小几乎是扶手椅形纳米管中的四倍。双极磁半导体是自旋热电子学应用的有前景的候选材料。
