標題: | Critical current of a ballistic asymmetric SNSNS junction |
作者: | Chang, VCY Chu, CS 電子物理學系 Department of Electrophysics |
關鍵字: | nanostructures;superconductors;electronic transport;tunneling |
公開日期: | 1998 |
摘要: | The critical current through an asymmetrically stacked, double superconductor-normal-metal-superconduct (SNS) junction is studied in the mesoscopic and ballistic regime. The asymmetry in such SNSNS junctions excludes any intuitive choice for the phase phi(2) of the middle superconductor S-2. We propose to determine phi(2) from the condition that the currents in the two normal regions are the same. The Bogoliubov-de Gennes equation is solved analytically within the Andreev approximation. In the long S2 limit, we find that the current-phase relation (CPR) can be constructed directly from the CPRs of the two constituent SNS junctions, of which the longer SNS junction imposes a cutoff to the critical current. In short S-2 cases, the cutoff feature remains, but the cutoff value is affected by the Andreev-level tunneling. The dependencies of the SNSNS critical current on the length of S-2, and the asymmetry in the configuration are studied. (C) 1998 Elsevier Science Ltd. All rights reserved. |
URI: | http://hdl.handle.net/11536/96 |
ISSN: | 0038-1098 |
期刊: | SOLID STATE COMMUNICATIONS |
Volume: | 107 |
Issue: | 8 |
起始頁: | 433 |
結束頁: | 438 |
顯示於類別: | 期刊論文 |