Conventional single-gap $s-$wave superconductivity and hidden peak effect in single crystals of Mo$_8$Ga$_{41}$ superconductor
Sunil Ghimire, Kyuil Cho, Kamal R. Joshi, Makariy A. Tanatar, Zhixiang Hu, Cedomir Petrovic, Ruslan Prozorov
SciPost Phys. 17, 117 (2024) · published 21 October 2024
- doi: 10.21468/SciPostPhys.17.4.117
- Submissions/Reports
Abstract
London and Campbell penetration depths were measured in single crystals of the endohedral gallide cluster superconductor, Mo$_8$Ga$_41$. The full temperature range superfluid density, $\rho_s(T)$, is consistent with the clean isotropic $s-$wave weak-coupling BCS theory without any signs of the second gap or strong coupling. The temperature dependence of the Campbell length is hysteretic between zero-field cooling (ZFC) and field-cooling (FC) protocols, indicating an anharmonic vortex pinning potential. The field dependence of the effective critical current density, $j_{c}(H)$, reveals an unusual result. While in the ZFC protocol, $j_{c}(H)$ is monotonically suppressed by the magnetic field, it exhibits a profound "hidden" peak effect in the FC protocol, that is, without a vortex density gradient. We suggest a possible novel mechanism for such a peak effect, which involves both static and dynamic aspects of vortex pinning.
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Sunil Ghimire,
- 1 2 Kyuil Cho,
- 1 2 Kamal R. Joshi,
- 1 2 Makariy Tanatar,
- 3 4 Zhixiang Hu,
- 3 4 5 6 Cedomir Petrovic,
- 1 2 Ruslan Prozorov
- 1 Iowa State University [ISU]
- 2 Ames Laboratory
- 3 Brookhaven National Laboratory [BNL]
- 4 Stony Brook University [SUNY Stony Brook]
- 5 中国科学院 / Chinese Academy of Sciences [CAS]
- 6 Универзитет у Београду / University of Belgrade