研究了半导体纳米线/超导体复合结构中的马约拉纳费米子的存在情况, 提出一种用相干光学谱探测马约拉纳费米子的全光学方法.将一束较强的泵浦激光和一束较弱的探测激光同时作用于半导体量子点, 由系统的哈密顿量导出半导体量子点的相干光学谱.数值模拟结果表明, 相干光学谱中呈现出由半导体量子点与马约拉纳费米子耦合诱导的明确的马约拉纳费米子迹象.半导体量子点与马约拉纳费米子之间的无接触性, 避免了探测中杂质信号的引入.半导体量子点与马约拉纳费米子间的耦合强度和探测吸收谱中两尖峰之间的分裂宽度呈正比, 可通过测量分裂宽度获得耦合强度, 为耦合强度的确定提供了直观的测量方法.

The existence of Majorana fermions in hybrid semiconductor/superconductor heterostructures was studied, and an all-optical method to probe the Majorana fermions by using coherent optical spectra was presented. A strong pump laser and a weak probe laser were acted on semiconductor quantum dot, and the coherent optical spectra were derived by the Hamiltonian of system. The numerical results indicate that the coherent optical spectra present a distinct signature of the coupling between the semiconductor quantum dot and the Majorana fermions in the optical detection method. The characteristic of non-contact between the semiconductor quantum dot and the Majorana fermions can make the detection process avoid introducing noises. The coupling strength between the semiconductor quantum dot and the Majorana fermions is proportional to the distance of two the peaks in the probe absorption spectrum, so that the coupling strength can be obtained by measuring the distance of two the peaks, which presents a straight forward means to determine the coupling strength.MOURIK V, ZUO K, FROLOV S M, et al. Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices［J］. Science, 2012, 336(6084): 1003-1007.