Time Reversal Breaking Superconducting State in the Phase Diagram of the Cuprates

Abstract

We review and extend a previous study on the symmetry of the superconducting state, stimulated by recent tunneling and Andreev reflection measurements giving robust evidences for the existence of a $d_{x^2-y^2}+i{d}_{xy}$ order parameter in the overdoped regime of two different cuprates. Looking for a possible second-order phase transition from a standard $d_{x^2-y^2}$ to a mixed and time reversal breaking state, we confirm the results of our previous analysis on La${}_{2-x}$Sr${}_x$CuO${}_4$. In the case of Y${}_{1-y}$Ca${}_y$Ba${}_2$Cu${}_3$O${}_{7-x}$ as well, among all the allowed symmetries, the $d_{x^2-y^2}+i{d}_{xy}$ is the most favored one and the unconventional state is likely to occur in a small dome of the phase diagram located in the optimal-overdoped region and at very low temperatures.

4 pages, 1 figure. Proceeding of SATT11 conference on Superconductivity. To appear in International Journal of Modern Physics B

References in corpus (2)

• Anomalous isotopic effect near the charge-ordering quantum criticality
• Evidence for pseudogap and phase-coherence gap separation by Andreev reflection experiments in Au/La_{2-x}Sr_{x}CuO_4 point-contact junctions