DYNAMICS OF THE COMPOSITE GAUGE BOSON IN THE CP(N-1) MODEL WITH FERMION AND THE CHARGE SPIN SEPARATION

We study the dynamics of the composite gauge boson in the CP(N-1) non-linear sigma model on a two-dimensional spatial lattice at finite temperature. In the pure CP(N-1) spin model, we map the system to the Polyakov-Susskind gauge model of deconfinement phase transition, and show that the disordered phase of spins corresponds to the confinement phase of gauge fields, while the ordered phase at zero temperature corresponds to the weak-coupling Higgs phase of gauge theory. Introduction of a non-relativistic gapless charged fermion generates non-local interactions of the gauge field and drives the system into the deconfinement phase at low temperature, indicating the phenomenon of charge-spin separation. These results pose important implications for studying normal-state properties of cuprate high-temperature superconductors using the t - J model in the slave-boson or slave-fermion representation.