Erlingsson Sigurdur I, Manolescu Andrei, Nemnes George Alexandru, Bardarson Jens H, Sanchez David
School of Science and Engineering, Reykjavik University, Menntavegur 1, IS-101 Reykjavik, Iceland.
University of Bucharest, Faculty of Physics, MDEO Research Center, 077125 Magurele-Ilfov, Romania.
Phys Rev Lett. 2017 Jul 21;119(3):036804. doi: 10.1103/PhysRevLett.119.036804.
We calculate the charge current generated by a temperature bias between the two ends of a tubular nanowire. We show that in the presence of a transversal magnetic field the current can change sign; i.e., electrons can either flow from the hot to the cold reservoir, or in the opposite direction, when the temperature bias increases. This behavior occurs when the magnetic field is sufficiently strong, such that Landau and snaking states are created, and the energy dispersion is nonmonotonic with respect to the longitudinal wave vector. The sign reversal can survive in the presence of impurities. We predict this result for core-shell nanowires, for uniform nanowires with surface states due to the Fermi level pinning, and for topological insulator nanowires.
我们计算了管状纳米线两端温度偏置所产生的充电电流。我们表明，在存在横向磁场的情况下，电流会改变方向；也就是说，当温度偏置增加时，电子既可以从热库流向冷库，也可以沿相反方向流动。当磁场足够强以至于产生朗道态和蛇形态，并且能量色散相对于纵向波矢是非单调的时候，就会出现这种行为。在存在杂质的情况下，符号反转依然存在。我们预测了核壳纳米线、由于费米能级钉扎而具有表面态的均匀纳米线以及拓扑绝缘体纳米线的这一结果。
