Multicritical Phenomena of Superconductivity and Antiferromagnetism in Organic Conductorκ-(BEDT-TTF)2X

Shuichi Murakami, Naoto Nagaosa
2000 Journal of the Physical Society of Japan  
We study theoretically the multicritical phenomena of the superconductivity (SC) and antiferromagnetism (AF) in organic conductors κ-BEDT salts. The phase diagram and the experimental data on the NMR relaxation rate 1/T_1 is analysed in terms of the renormalization group method. The bicritical phenomenon observed experimentally indicates the rotational symmetry, i.e., SO(5) symmetry, of the SC and the AF. The critical exponent x for the divergence of 1/T_1 is well explained by x = ν (z - 1 - η)
more » ... with the dynamical exponent z = 3/2 for the AF region while z = ϕ/ν∼ 1.84 at the bicritical point. These results strongly suggest that the origin of the SC is in common with that of the AF and that its symmetry is d-wave.
doi:10.1143/jpsj.69.2395 fatcat:jakhtnuvvzflfkcvdt2cmditni