Dresden 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 13: Superconductivity: Fe-based Superconductors - 122

TT 13.3: Vortrag

Montag, 20. März 2017, 15:30–15:45, HSZ 103

Search for broken time reversal symmetry of the superconducting order parameter in Ba_1−xK_xFe₂As₂ — •Vadim Grinenko¹, Philipp Materne¹, Rajib Sarkar¹, Sirko Kamusella¹, Hubertus Luetkens², Kunihiro Kihou³, Chul-Ho Lee³, Shavkat Akhmadaliev⁴, Dmitriy Efremov⁵, Stefan-Ludwig Drechsler⁵, and Hans-Henning Klauss¹ — ¹Institute for Solid State Physics, TU Dresden, D-01069, Germany — ²Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland — ³National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8560 Japan — ⁴Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany — ⁵IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany

Multi-band iron pnictides superconductors provide a unique possibility to study the effect of competing interactions on the superconducting (SC) order parameter symmetry. In Ba_1−xK_xFe₂As₂ a change of the SC order parameter symmetry at high K doping level x was predicted theoretically by S. Maiti et al., Phys Rev. B 91, 161102(R) (2015). This change occurs through an intermediate state with a complex order parameter which can lead to spontaneous currents below the SC critical temperature T_c. Here we report our muon spin rotation/relaxation (µSR) experiments on single crystalline samples of the title compound. In our experiments we observe an enhancement of the zero field muon relaxation rate below T_c for the sample with x ≈ 0.7. This result is interpreted as an evidence for the complex SC order parameter at this doping level.