Pseudogap, competing order and coexistence of staggered flux and d-wave pairing in high-temperature superconductors

TL;DR

This paper investigates the interplay between staggered flux order and d-wave superconductivity in high-T_c superconductors using a large-N theoretical approach to the t-J-V model, revealing phase competition and coexistence across doping levels.

Contribution

It introduces a large-N theoretical framework that treats Coulomb interaction and exchange on equal footing, providing new insights into phase behavior in doped Mott insulators.

Findings

Coexistence of staggered flux and d-wave superconductivity in underdoped regime

Disappearance of superconductivity in overdoped regime

Phase diagram illustrating competition and coexistence of orders

Abstract

We study the t-J-V model of a doped Mott insulator in connection to high-T_c superconductors. The nearest neighbor Coulomb interaction (V) is treated quantum mechanically on equal footing as the antiferromagnetic exchange interaction (J). Motivated by the SU(2) symmetry at half-filling, we construct a large-N theory which allows a systematic study of the interplay between staggered flux order and superconductivity upon doping. We solve the model in the large-N limit and obtain the ground state properties and the phase diagram as a function of doping. We discuss the competition and the coexistence of the staggered flux and the d-wave superconductivity in the underdoped regime and the disappearance of superconductivity in the overdoped regime