K. Kuboki et M. Sigrist, PROXIMITY-INDUCED TIME-REVERSAL SYMMETRY-BREAKING AT JOSEPHSON-JUNCTIONS BETWEEN D-WAVE SUPERCONDUCTORS, Czechoslovak journal of Physics, 46, 1996, pp. 1039-1040
Based on a Ginzburg Landau (GL) theory, it is shown that under certain
conditions a locally time-reversal symmetry breaking state can occur
at Josephson junctions between unconventional, in particular, d-wave s
uperconductors. Numerical solutions of the GL equations derived from t
he t - J model within a slave-boson mean-field approach show this effe
ct for realistic choices of parameters. An experiment to test the rele
vance of this theory to High-T-c superconductors is proposed.