Phase Diagram of a Superconducting and Antiferromagnetic System with SO(5) Symmetry
arXiv:cond-mat/9812031 · doi:10.1103/PhysRevLett.82.2568
Abstract
Temperature vs. chemical-potential phase diagrams of an SO(5) model for high-(T_c) cuprates are calculated by Monte Carlo simulation. There is a bicritical point where the second-order antiferromagnetism (AF) and superconductivity transition lines merge tangentially into a first-order line, and the SO(5) symmetry is achieved. In an external magnetic field, the AF ordering is first order in the region where the first-order melting line of flux lattice joins in. There is a tricritical point on the AF transition line from which the AF ordering becomes second order.
6 pages, 5 postscript figures, RevTex