Regular Article

Competing orders in an extended Falicov-Kimball model

¹ Department of Physics, The Ohio State University, Columbus 43210, OH, USA
² Department of Physics, Jhargram Raj College, Jhargram 721507, West Bengal, India

^a e-mail: pradhan.61@osu.edu

Received: 6 June 2019
Received in final form: 8 August 2019
Published online: 2 October 2019

Abstract

We study the interplay between superconducting pairing, exciton and charge-density wave in a correlated electron model, the Falicov-Kimball model, extended by a hybridization term between spinless fermions and also by an attractive pairing in the particle channel. A self-consistent Hartree-Fock BdG mean-field calculation shows that the hybridization V and Coulomb repulsion U favour in binding an exciton but both are detrimental to the formation of superconducting pairing, whereas, CDW is favoured by Coulomb interaction and disfavoured by V . There is a coexistence regime for superconductivity, CDW and excitonic order in the parameter space.