As the spin-triplet superconductivity arises from the condensation of spinful Cooper pairs, its full characterization requires not only charge ordering, but also spin ordering. For a two-dimensional (2D) easy-plane spin-triplet superconductor, this naively seems to suggest the possibility of two distinct Berezinskii-Kosterlitz-Thouless (BKT) phase transitions, one in the charge sector and the other in the spin sector. However, it has been recognized that there are actually three possible BKT transitions, involving the deconfinement of, respectively, the conventional vortices, the merons and the half-quantum vortices with vorticity in both the charge and the spin current. By considering equal-spin-pairing spin-triplet superconductors with bulk spin degeneracy, we show how all the transitions can be characterized by the relation between the voltage drop and the spin-polarized current bias. This study reveals that, due to the hitherto unexamined transport of half-quantum vortices, there is an upper bound on the spin supercurrent in a quasi-long range ordered spin-triplet superconductor, which provides a means for half-quantum vortex detection via transport measurements and deeper understanding of fluctuation effects in superconductor-based spintronic devices.
Cited by 2
Maccari et al., Effects of intercomponent couplings on the appearance of time-reversal symmetry breaking fermion-quadrupling states in two-component London models
Phys. Rev. B 105, 214520 (2022) [Crossref]
Garaud et al., Effective Model and Magnetic Properties of the Resistive Electron Quadrupling State
Phys. Rev. Lett. 129, 087602 (2022) [Crossref]
Authors / Affiliations: mappings to Contributors and OrganizationsSee all Organizations.
- 1 2 3 Suk Bum Chung,
- 4 Se Kwon Kim
- 1 서울대학교 / Seoul National University [SNU]
- 2 고등과학원 / Korea Institute for Advanced Study [KIAS]
- 3 서울시립대학교 / University of Seoul [UoS]
- 4 한국과학기술원 / Korea Advanced Institute of Science and Technology [KAIST]