1/2 (e2/h) Conductance Plateau without 1D Chiral Majorana Fermions
1/2 (e2/h) Conductance Plateau without 1D Chiral Majorana Fermions
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DOI：
10.1103/physrevlett.120.107002
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发表时间：
2018-03-09
影响因子：
8.6
通讯作者：
Wen, Xiao-Gang
中科院分区：
文献类型：
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作者：
Ji, Wenjie;Wen, Xiao-Gang
我们解决了最近在超导 (SC) 薄膜覆盖的整数量子霍尔 (IQH) 薄膜实验中观察到的 1/2 (e(2)/h) 电导平台的起源问题。由于上述装置边缘的一维（1D）手性马约拉纳费米子可以产生半量子化平台，因此这样的平台被认为是手性马约拉纳费米子的确凿证据。然而，在这封信中，我们给出了 1/2 (e(2)/h) 电导平台的另一种机制。我们发现 1/2 (e(2)/h) 电导平台是 IQH 薄膜和 SC 薄膜之间良好电接触的一般特征，并且无法区分一维手性马约拉纳费米子是否存在。我们还发现超导体和 IQH 边缘通道之间的接触电导具有非欧姆形式 sigma(SC-Hall)，与 k(B)T 中的 V-2 成比例
We address the question about the origin of the 1/2 (e(2)/h) conductance plateau observed in a recent experiment on an integer quantum Hall (IQH) film covered by a superconducting (SC) film. Since one-dimensional (1D) chiral Majorana fermions on the edge of the above device can give rise to the half quantized plateau, such a plateau is regarded as conclusive evidence for the chiral Majorana fermions. However, in this Letter we give another mechanism for the 1/2 (e(2)/h) conductance plateau. We find the 1/2 (e(2)/h) conductance plateau to be a general feature of a good electric contact between the IQH film and the SC film, and cannot distinguish the existence or the nonexistence of 1D chiral Majorana fermions. We also find that the contact conductance between a superconductor and an IQH edge channel has a non-Ohmic form sigma(SC-Hall) proportional to V-2 in the k(B)T