Gauge Theory of Strongly Correlated Electronic Systems

N. I. Karchev

T. Senthil, Matthew P. A. Fisher

Recently, we have elucidated the physics of electron fractionalization in strongly interacting electron systems using a Z 2 gauge theory formulation. Here we discuss the connection with the earlier U (1) gauge theory approaches based on the slave boson mean field theory. In particular, we identify the relationship between the holons and Spinons of the slave-boson theory and the true physical excitations of the fractionalized phases that are readily described in the Z 2 approach.

Ikuo Ichinose, Tetsuo Matsui

In a recent Letter, Nayak argued that slave partices are always confined in gauge theories of strongly-correlated electron systems like the t-J model. The argument mostly relies on Elitzur's theorem and the fact that the effective gauge theory under discussion is at infinite coupling. On the other hand, in the previous papers we studied dynamics of the gauge theory of the t-J model showing that the slave particles are in the Coulomb phase below certain critical temperature T{CSS} that depends on hole doping. We comment on the discrepancy between the results in two papers.

Naoto Nagaosa

N. I. Karchev

Relation between strongly correlated electronic systems and anyonlike systems is established. A U(1) gauge theory is developed for the frustrated Hubbard model in the limit of infinite on-site Coulomb repulsion. An effective Chern-Simons theory, which describes chiral spin liquids is obtained. The fermions (holes) are coupled to the gauge fields creating thus an anyonlike system. I show that under some circumstances the system is a superconductor for special value of the hole density.

Naoto Nagaosa