Patiño Edgar J, Lozano-Gómez Daniel
Superconductivity and Nanodevices Laboratory, Departamento de Física, Universidad de los Andes, Carrera 1 No. 18A-12, A.A. 4976-12340, Bogotá, Colombia.
School of Physical Sciences and Nanotechnology, Yachay Tech University, Urcuquí, Ecuador.
Sci Rep. 2021 Apr 27;11(1):9050. doi: 10.1038/s41598-021-88228-1.
We propose a simple phenomenological theory for quantum tunneling of Cooper pairs, in superconductor/insulator/superconductor tunnel junctions, for a regime where the system can be modeled as bosonic particles. Indeed, provided there is an absence of quasiparticle excitations (fermions), our model reveals a rapid increase in tunneling current, around zero bias voltage, which rapidly saturates. This manifests as a zero bias conductance peak that strongly depends on the superconductors temperature in a non-monotonic way. This low energy tunneling of Cooper pairs could serve as an alternative explanation for a number of tunneling experiments where zero bias conductance peak has been observed.
我们针对超导体/绝缘体/超导体隧道结中库珀对的量子隧穿提出了一种简单的唯象理论，适用于系统可被建模为玻色子粒子的情况。实际上，若不存在准粒子激发（费米子），我们的模型显示，在零偏置电压附近，隧穿电流会迅速增加，然后迅速饱和。这表现为一个零偏置电导峰，它以非单调的方式强烈依赖于超导体的温度。库珀对的这种低能隧穿可以为一些观察到零偏置电导峰的隧穿实验提供另一种解释。
