拓扑超导体与量子点结构中非简并能级的全计数统计  

Full counting statistics of non⁃degenerate energy levels in topological superconductor coupled to a quantum dot

作　　者：王静[1] 郭健宏[1] WANG Jing;GUO Jianhong(Department of Physics,Capital Normal University,Beijing 100048)

机构地区：[1]首都师范大学物理系,北京100048

出　　处：《首都师范大学学报（自然科学版）》2021年第1期20-24,共5页Journal of Capital Normal University：Natural Science Edition

摘　　要：利用占据数方程研究拓扑超导体与量子点中非简并能级的全计数统计.在有限温度与偏压下,将计数统计的各阶累计矩表示为特征多项式的各项系数及其导数.通过计数统计,Majorana费米子总是导致微分电导峰,与费米子宇称是否简并无关.在大偏压区,噪声明显增大,呈超泊松分布.当费米子宇称非简并时,噪声减小,呈亚泊松分布.偏离度在大偏压区对Majorana费米子更为敏感.说明有限温度与有限电压条件下的电流全计数统计可以表征Majorana费米子.Full counting statistics of non⁃degenerate energy levels in topological superconductor coupled to a quantum dot was studied by the equation of population.In the regime of finite temperature and bias voltage,the time⁃scaled current cumulants can be expressed by the coefficients and their derivatives in the characteristic polyno⁃mial of the equation of population.It was illustrated that Majorana fermions always lead to the appearance of zero⁃bi⁃as peak of conductance,which had nothing to do with whether the fermion parity was degenerate.At large bias volt⁃age,the noise was enhanced by Majorana fermions,which resulted in super⁃Poisson distribution.When the fermi⁃ons parity was non⁃degenerate,the noise was reduced and the distribution was sub⁃Poisson.The deviation degree was more sensitive to Majorana fermions in the large bias region.It showed that the current full counting statistics at finite temperature and voltage can characterize Majorana fermions.

关 键 词：拓扑超导体 量子点 Majorana费米子 

分 类 号：O469[理学—凝聚态物理]