Effect of incommensurate potential on the resonant tunneling through Majorana bound states on the topological superconductor chains
Effect of incommensurate potential on the resonant tunneling through Majorana bound states on the topological superconductor chains
复制标题
不通约电势对拓扑超导链上马约拉纳束缚态共振隧道效应的影响
DOI：
10.1140/epjb/e2014-50216-0
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发表时间：
2014-07
影响因子：
1.6
通讯作者：
Gao Xianlong
中科院分区：
文献类型：
--
作者：
Pei Wang;Shu Chen;Gao Xianlong
本文用数值算符方法研究了具有无公度势的Kitaev链与两个正常引线耦合的输运问题。我们发现了一个量子化的线性电导为fe ~ 2/h，在很宽的范围内与无序强度和栅电压无关，表明了Majorana束缚态的存在.而在有限偏压下，无公度势抑制了电流，使I-V曲线的线性响应区变窄，I-V曲线呈现出两个分别对应于超导带隙和带边的平台。当无序强度达到临界值2gs+ 2Δ时，线性电导突然降为零，Δ为p波对振幅，gs为相邻位置间的跳跃，对应于拓扑超导相到安德森局域相的转变.改变栅极电压也会导致线性电导的突然下降，通过驱动链进入拓扑平凡的超导相，whoseI-V曲线呈现指数形状。
We study the transport through the Kitaev chain with incommensurate potentials coupled to two normal leads by the numerical operator method. We find a quantized linear conductance ofe2/h, which is independent to the disorder strength and the gate voltage in a wide range, signaling the Majorana bound states. While the incommensurate potential suppresses the current at finite voltage bias, and then narrows the linear response regime of theI-Vcurve which exhibits two plateaus corresponding to the superconducting gap and the band edge, respectively. The linear conductance abruptly drops to zero as the disorder strength reaches the critical value 2gs+ 2ΔwithΔthep-wave pairing amplitude andgsthe hopping between neighbor sites, corresponding to the transition from the topological superconducting phase to the Anderson localized phase. Changing the gate voltage also causes an abrupt drop of the linear conductance by driving the chain into the topologically trivial superconducting phase, whoseI-Vcurve exhibits an exponential shape.