A Field Theory Approach to the $t$-$J$ Model and the Spin-Charge Separation

Abstract

We analyze the $t$-$J$ model using the ${\mathrm{CP}}^1$ representation for the slave operators (holons and spinons) which is particularly suited to study the phenomenon of the spin-charge separation in strongly correlated electron systems. In particular, we show that for the one-dimensional $t$-$J$ model below half-filling the low energy effective dynamics of the spin and charge degrees of freedom is represented in the continuum limit by a ${\mathrm{CP}}^1$ model with a topological term, minimally coupled to a massless Dirac field with a four-fermion interaction. The bosonic term of this action describes the spin waves produced by the spinons, while the fermionic term represents the low energy charge excitations. This theory exhibits explicitly a local abelian gauge invariance.

arXiv comment27 pp., TeX file (1 figure on request), DFT-US 1/94

References in corpus (2)

• Fermion-Spin Transformation to Implement the Charge-Spin Separation
• Slave Anyons in the $t$-$J$ Model at the Supersymmetric Point