Effects of intercomponent couplings on the appearance of time-reversal symmetry breaking fermion-quadrupling states in two-component London models

Detection of a bosonic metallic state that breaks the Z2 time-reversal symmetry has been recently reported in Ba1???xKxFe2As2 with a doping level x ??? 0.8. This is a metallic state of fermionic quadruplets that breaks time-reversal symmetry. As such, it has no condensed Cooper pairs but has a long-range order between fermionic quartets. In the present paper, we investigate the emergence of this phase in a two-component London model via Monte Carlo simulations as a function of various intercomponent couplings.

Automated summary

A bosonic metallic state that breaks the Z2 time-reversal symmetry has been detected recently in Ba1???xKxFe2As2. Monte Carlo simulations were conducted to investigate the emergence of this phase in a two-component London model.