d波YBa2Cu3O7-δ约瑟夫森结中的宏观量子隧穿

Macroscopic quantum tunneling in d-wave YBa2Cu3O7-delta Josephson junctions.

作者信息

Bauch T, Lombardi F, Tafuri F, Barone A, Rotoli G, Delsing P, Claeson T

机构信息

Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-412 96 Göteborg, Sweden.

出版信息

Phys Rev Lett. 2005 Mar 4;94(8):087003. doi: 10.1103/PhysRevLett.94.087003. Epub 2005 Mar 3.

DOI:10.1103/PhysRevLett.94.087003

PMID:15783922

Abstract

The escape rate from the zero voltage state in a superconducting Josephson junction (JJ) is determined by the temperature, but it saturates at low temperature due to macroscopic quantum tunneling (MQT). Complications due to d-wave symmetry in a high temperature superconductor, like low energy quasiparticles and an unconventional current-phase relation, may influence the escape rate. We report, for the first time to our knowledge, the observation of MQT in a YBa(2)Cu(3)O(7-delta) grain boundary biepitaxial JJ. This proves that dissipation can be significantly reduced by a proper junction configuration, which is of significance for quantum coherence.

摘要

超导约瑟夫森结（JJ）中从零电压态的逃逸率由温度决定，但在低温下由于宏观量子隧穿（MQT）会达到饱和。高温超导体中d波对称性带来的复杂情况，如低能准粒子和非常规电流-相位关系，可能会影响逃逸率。据我们所知，我们首次报道了在YBa₂Cu₃O₇₋₈晶粒边界双外延约瑟夫森结中观察到宏观量子隧穿。这证明通过适当的结配置可以显著降低耗散，这对量子相干具有重要意义。