Photon-assisted tunneling through a topological superconductor with Majorana bound states
Photon-assisted tunneling through a topological superconductor with Majorana bound states
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DOI：
10.1063/1.4939096
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发表时间：
2015-12
期刊：
影响因子：
1.6
通讯作者：
Han-Zhao Tang;Ying-Tao Zhang;Jian‐Jun Liu
中科院分区：
文献类型：
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作者：
Han-Zhao Tang;Ying-Tao Zhang;Jian‐Jun Liu
采用Keldysh非平衡绿色函数方法，研究了高频微波场作用下具有Majorana束缚态的拓扑超导体的含时输运.研究发现，光子辅助隧穿驱动的Majorana束缚态可以吸收（发射）光子，光子辅助隧穿边带峰可以分裂Majorana束缚态，并在非零偏压下出现。这种分裂打破了目前认为Majorana束缚态只在零偏压下出现的观点，从而为在非零能量模式下探测Majorana束缚态提供了一种新的实验方法。我们不仅证明了光子辅助隧穿边带峰是由非零能量的Majorana束缚态引起的，而且还证明了光子辅助隧穿边带峰的高度与微波场的强度有关.进一步表明，由Majorana束缚态诱导的时变电导在一定时间内呈现负值，这对应于介观系统中相位相干时变行为的一种表现.
Employing the Keldysh Nonequilibrium Green’s function method, we investigate time-dependent transport through a topological superconductor with Majorana bound states in the presence of a high frequency microwave field. It is found that Majorana bound states driven by photon-assisted tunneling can absorb(emit) photons and the resulting photon-assisted tunneling side band peaks can split the Majorana bound state that then appears at non-zero bias. This splitting breaks from the current opinion that Majorana bound states appear only at zero bias and thus provides a new experimental method for detecting Majorana bound states in the Non-zero-energy mode. We not only demonstrate that the photon-assisted tunneling side band peaks are due to Non-zero-energy Majorana bound states, but also that the height of the photon-assisted tunneling side band peaks is related to the intensity of the microwave field. It is further shown that the time-varying conductance induced by the Majorana bound states shows negative values for a certain period of time, which corresponds to a manifestation of the phase coherent time-varying behavior in mesoscopic systems.