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).
@article{arxiv.1109.2753,
title = {Spectrum of Andreev bound states in Josepshon junctions with a ferromagnetic insulator},
author = {Shiro Kawabata and Yukio Tanaka and Alexander A. Golubov and Andrey S. Vasenko and Yasuhiro Asano},
journal= {arXiv preprint arXiv:1109.2753},
year = {2013}
}
Comments
6 pages, 5 figures, Invited Report on the Moscow International Symposium on Magnetism MISM2011