Superconducting Order Parameter Structure in the Nematic Phase of Iron-based Materials

Korshunov, M.M., Togushova, Y.N.// JETP Letters//

https://doi.org/10.1134/S0021364024600046

We consider the effect of the nematic order on the formation of the superconducting state in iron pnictides and chalcogenides. Nematic order with the B_2g symmetry is modelled as the d-type Pomeranchuk instability and treated within the mean-field approach. Calculated nematic order parameter depends on the nematic interaction coefficient and abruptly changes with the coefficient’s increase. The superconducting solution is obtained within the spin-fluctuation pairing theory. We show that the leading solution in the nematic phase has a s_π± structure. From the critical temperature T_c estimations, we conclude that the nematic superconducting state of the s_π± type is more favorable than the usual s_± and $d_{x^{2} - y^{2}}$ type states appearing in the absence of the nematicity