New surprises in the t-J model: implications for Cuprates

The t-J model is a paradigmatic model for the study of strongly correlated electron systems. In particular, it has been argued that it is an appropriate model to describe the cuprate high-T_c superconductors. It turns out that a comprehensive understanding of the gamut of Physics encoded by the t-J model is still an open problem. In recent years some remarkable experiments on the cuprates, for example, discovery of nodeless superconductivity in underdoped samples, discovery of s-wave like gap in the pseudogap phase), and observation of polar Kerr effect (PKE), have thrown up new challenges for this model. Presented here are results demonstrating that, within the slave-particle formulation of the t-J model, the d-wave superconductor is unstable at low doping to its own anti-symmetric phase mode fluctuations when the effect of fluctuations is treated self-consistently