mu SR study of time-reversal symmetry constraints and bulk superfluid response in Li 0.95 FeAs
Researchers used zero-field and transverse-field muon-spin rotation/relaxation ($ƼmSR$) on superconducting Li0.95FeAs to study its bulk properties. The study found no evidence of time-reversal symmetry breaking in the superconducting state, which rules out certain complex order parameters. It also characterized the bulk superfluid response using a two-gap model, reconciling gap values reported by different experimental techniques.