Nonlinear Seebeck and Peltier effects in a Majorana nanowire coupled to leads  

作　　者：迟锋 刘佳 付振国 刘黎明 易子川 Feng Chi;Jia Liu;Zhenguo Fu;Liming Liu;Zichuan Yi(School of Electronic and Information Engineering,UESTC of China,Zhongshan Institute,Zhongshan 528400,China;School of Science,Inner Mongolia University of Science and Technology,Baotou 014010,China;Institute of Applied Physics and Computational Mathematics,Beijing 100088,China)

机构地区：[1]School of Electronic and Information Engineering,UESTC of China,Zhongshan Institute,Zhongshan 528400,China [2]School of Science,Inner Mongolia University of Science and Technology,Baotou 014010,China [3]Institute of Applied Physics and Computational Mathematics,Beijing 100088,China

出　　处：《Chinese Physics B》2024年第7期547-552,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.12264037);the Innovation Team of Colleges and Universities in Guangdong Province(Grant No.2021KCXTD040);Guangdong Province Education Department(Grant No.2023KTSCX174);the Key Laboratory of Guangdong Higher Education Institutes(Grant No.2023KSYS011);Science and Technology Bureau of Zhongshan(Grant No.2023B2035)。

摘　　要：We theoretically study nonlinear thermoelectric transport through a topological superconductor nanowire hosting Majorana bound states(MBSs) at its two ends, a system named as Majorana nanowire(MNW). We consider that the MNW is coupled to the left and right normal metallic leads subjected to either bias voltage or temperature gradient. We focus our attention on the sign change of nonlinear Seebeck and Peltier coefficients induced by mechanisms related to the MBSs, by which the possible existence of MBSs might be proved. Our results show that for a fixed temperature difference between the two leads, the sign of the nonlinear Seebeck coefficient(thermopower) can be reversed by changing the overlap amplitude between the MBSs or the system equilibrium temperature, which are similar to the cases in linear response regime. By optimizing the MBS–MBS interaction amplitude and system equilibrium temperature, we find that the temperature difference may also induce sign change of the nonlinear thermopower. For zero temperature difference and finite bias voltage, both the sign and magnitude of nonlinear Peltier coefficient can be adjusted by changing the bias voltage or overlap amplitude between the MBSs. In the presence of both bias voltage and temperature difference, we show that the electrical current at zero Fermi level and the states induced by overlap between the MBSs keep unchanged, regardless of the amplitude of temperature difference. We also find that the direction of the heat current driven by bias voltage may be changed by weak temperature difference.

关 键 词：quantum dot nonlinear Seebeck coefficient Peltier coefficient Majorana bound states sign change 

分 类 号：O469[理学—凝聚态物理]