当前位置: X-MOL 学术SciPost Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Conductance asymmetries in mesoscopic superconducting devices due to finite bias
SciPost Physics ( IF 5.5 ) Pub Date : 2021-02-16 , DOI: 10.21468/scipostphys.10.2.037
André Melo 1 , Chun-Xiao Liu 1 , Piotr Rożek 1 , Tómas Örn Rosdahl 1 , Michael Wimmer 1
Affiliation  

Tunneling conductance spectroscopy in normal metal-superconductor junctions is an important tool for probing Andreev bound states in mesoscopic superconducting devices, such as Majorana nanowires. In an ideal superconducting device, the subgap conductance obeys specific symmetry relations, due to particle-hole symmetry and unitarity of the scattering matrix. However, experimental data often exhibits deviations from these symmetries or even their explicit breakdown. In this work, we identify a mechanism that leads to conductance asymmetries without quasiparticle poisoning. In particular, we investigate the effects of finite bias and include the voltage dependence in the tunnel barrier transparency, finding significant conductance asymmetries for realistic device parameters. It is important to identify the physical origin of conductance asymmetries: in contrast to other possible mechanisms such as quasiparticle poisoning, finite-bias effects are not detrimental to the performance of a topological qubit. To that end we identify features that can be used to experimentally determine whether finite-bias effects are the source of conductance asymmetries.

中文翻译:

由于有限偏置,介观超导器件中的电导不对称

正常金属-超导体结中的隧道电导光谱学是探测介观超导器件(如马约拉纳纳米线)中安德列夫键态的重要工具。在理想的超导装置中,由于粒子-孔的对称性和散射矩阵的统一性,子间隙电导遵循特定的对称关系。但是,实验数据通常显示出与这些对称性甚至明显的破坏的偏差。在这项工作中,我们确定了一种导致电导不对称而不会发生准粒子中毒的机制。特别是,我们研究了有限偏置的影响,并将电压相关性包括在隧道势垒的透明性中,发现实际器件参数存在明显的电导不对称性。识别电导不对称的物理原因很重要:与其他可能的机制(如准粒子中毒)相比,有限偏置效应对拓扑量子位的性能无害。为此,我们确定了可用于实验确定有限偏置效应是否是电导不对称源的特征。
更新日期:2021-02-16
down
wechat
bug