Fluctuation Effects of Gauge Fields in the Slave-Boson t-J Model

Abstract

We present a quantitative study of the charge-spin separation (CSS) phenomenon in a U(1) gauge theory of the t-J model of high-T_c superconductors.We calculate the critical temperature T_CSS of a confinement-deconfinement phase transition as a function of hole doping δ, below which the CSS takes place. Fluctuationsof gauge fields are so large that T_CSS is reduced to about 10% of its mean-field value. We also make some comments on the phase structure from a gauge-theoretical point of view.