Superconductivity with broken time-reversal symmetry in ion-irradiated Ba&lt;sub&gt;0.27&lt;/sub&gt;K&lt;sub&gt;0.73&lt;/sub&gt;Fe&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt; single crystals

Grinenko, V.; Materne, P.; Sarkar, R.; Luetkens, H.; Kihou, K.; Lee, C.H.; Akhmadaliev, S.; Efremov, D.V.; Drechsler, S.-L.; Klauss, H.-H.

doi:10.1103/PhysRevB.95.214511

Superconductivity with broken time-reversal symmetry in ion-irradiated Ba_0.27K_0.73Fe₂As₂ single crystals

Grinenko V, Materne P, Sarkar R, Luetkens H, Kihou K, Lee CH, Akhmadaliev S, Efremov DV, Drechsler S-L & Klauss H-H

Citation

Grinenko, V., Materne, P., Sarkar, R., Luetkens, H., Kihou, K., Lee, C. H., … Klauss, H. H. (2017). Superconductivity with broken time-reversal symmetry in ion-irradiated Ba_0.27K_0.73Fe₂As₂ single crystals. Physical Review B, 95(21), 214511 (5 pp.). https://doi.org/10.1103/PhysRevB.95.214511

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:4399

Over the past years a lot of theoretical and experimental effort has been made to find states with broken time-reversal symmetry (BTRS) in multiband superconductors. In particular, it was proposed theoretically that in the Ba_1-xK_xFe₂As₂ system either an s + is or an s + id BTRS state may exist at high doping levels in a narrow region of the phase diagram. Here we report the observation of an enhanced zero-field muon spin-relaxation rate below the superconducting transition temperature for a high quality crystalline sample with x ≈ 0.73. This indicates that indeed the time-reversal symmetry is broken in superconducting Ba_1-_xK_xFe₂As₂ at this doping level.