具有诱导超导电性和自旋轨道耦合作用的半导体纳米线零偏压电导峰的研究

A Study of Zero Bias Conductance Peak in Spin-Orbit Coupled Semiconductor Nanowires with Induced Superconducting Pair Potential

基于凝聚态系统可产生具有马约拉纳费米子特性的准粒子态的理论,考虑到零偏压电导峰是否可以作为马约拉纳费米子准粒子束缚态存在的证据在理论上还存在争议,采用详细的理论计算和分析方法,对具有诱导超导电性和自旋轨道耦合作用的半导体纳米线的微分电导谱的一些特性进行了分析和研究,其中主要研究系统的微分电导谱与系统的各种可调控参量之间的关系.结果表明:这类系统中存在2种不同类型的零偏压电导峰,这2种零偏压电导峰具有不同的特点,由不同的物理机制所致.文中的计算结果对澄清最近一些有争议性的理论问题有一定的理论参考意义.

Based on the theoretical model of the condensed system generating quasi-particle states with Majorana fermions’ characteristics and using more elaborate theoretical calculations,a detailed analysis is conducted of charge transport through semiconductor nanowire with the interplay of Rashba spin-orbit coupling and induced superconducting pair potential with reference to the theoretical controversy over whether the zero bias conductance peak can be used as the evidence for the existence of quasi-particle bound states of Majorana fermions. It is shown that in such systems there may exist two different types of zero-bias conductance peaks,which have different characteristics and should be attributed to different physical mechanisms. The results may help to clarify some controversial issues concerning the theoretical interpretation of some recent experimental results.