Josephson pi state in a ferromagnetic insulator.
We predict anomalous atomic-scale 0-pi transitions in a Josephson junction with a ferromagnetic-insulator (FI) barrier. The ground state of such junction alternates between 0 and pi states when thickness of FI is increasing by a single atomic layer. We find that the mechanism of the 0-pi transition can be attributed to thickness-dependent phase shifts between the wave numbers of electrons and holes in FI. Based on these results, we show that a stable pi state can be realized in junctions based on high-T{c} superconductors with a La2BaCuO5 barrier.
Kawabata
Shiro
S
Nanotechnology Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), and JST-CREST, Tsukuba, Ibaraki, 305-8568, Japan.
Asano
Yasuhiro
Y
Tanaka
Yukio
Y
Golubov
Alexander A
AA
Kashiwaya
Satoshi
S