CP1|1 nonlinear sigma model vs strong electron correlations

The nonlinear sigma model targeted on the coset supermanifold CP1 vertical bar 1 = SU(2 vertical bar 1)/U(1 vertical bar 1) is derived in an attempt to describe the quasiclassical low-energy effective action for the doped t - J model at the SUSY point, J = 2t. In spite of the fact that the supermanifold CP1 vertical bar 1 indeed appears as the phase space of the strongly correlated electrons, the canonical CP1 vertical bar 1 nonlinear sigma model (NLSM) is unable to capture the physics of strong correlations displayed by the SUSY t J model at any finite doping. This is due to the fact that, in this regime, the doping itself cannot be self-consistently incorporated into the CP1 vertical bar 1 NLSM. (C) 2017 Elsevier Inc. All rights reserved.