Quantum point contact as a probe of a topological superconductor
Quantum point contact as a probe of a topological superconductor
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DOI：
10.1088/1367-2630/13/5/053016
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发表时间：
2011-05-12
影响因子：
3.3
通讯作者：
Beenakker, C. W. J.
中科院分区：
文献类型：
--
作者：
Wimmer, M.;Akhmerov, A. R.;Beenakker, C. W. J.
我们计算了平行磁场中自旋轨道耦合半导体中s波邻近效应产生的弹道点接触到超导导线的电导。当超导体处于拓扑非平凡相时，电导G作为接触宽度或费米能的函数，在4 e（2）/h的半整数倍处出现平台。相比之下，高原是在通常的整数倍，在拓扑平凡阶段。无序破坏了除第一个平台之外的所有平台，第一个平台保持精确的量化，与之前隧道接触的结果一致。作为拓扑相的探针，弹道接触优于隧道接触的优点是对有限电压或温度的灵敏度大大降低。
We calculate the conductance of a ballistic point contact to a superconducting wire, produced by the s-wave proximity effect in a semiconductor with spin-orbit coupling in a parallel magnetic field. The conductance G as a function of contact width or Fermi energy shows plateaux at half-integer multiples of 4e(2)/h if the superconductor is in a topologically nontrivial phase. In contrast, the plateaux are at the usual integer multiples in the topologically trivial phase. Disorder destroys all plateaux except the first, which remains precisely quantized, consistent with previous results for a tunnel contact. The advantage of a ballistic contact over a tunnel contact as a probe of the topological phase is the strongly reduced sensitivity to finite voltage or temperature.