Spectrum of Andreev bound states in Josephson junctions with a ferromagnetic insulator

[摘要] Ferromagnetic-insulator (FI) based Josephson junctions are promising candidates for a coherent superconducting quantum bit as well as a classical superconducting logic circuit. Recently the appearance of an intriguing atomic-scale 0-pi transition has been theoretically predicted. In order to uncover the mechanism of this phenomena, we numerically calculate the spectrum of Andreev bound states in a FI barrier by diagonalizing the Bogoliubov-de Gennes equation. We show that Andreev spectrum drastically depends on the parity of the FI-layer number L and accordingly the pi(0) state is always more stable than the 0 (pi) state if L is odd (even). (C) 2012 Elsevier B.V. All rights reserved.

[发布日期] 2012-10-01

[效力级别]  Proceedings Paper

[关键词] Josephson junction;Spintronics;Ferromagnetic insulator;Quantum bit;Andreev bound state;Tight binding model