Two-dimensional superconductors undergo a Berezinskii-Kosterlitz-Thouless transition driven by vortex-antivortex unbinding, yet experimental signatures beyond transport remain limited. Here, we show that the spin-lattice relaxation rate provides a direct probe of this transition. In a 2-dimensional s-wave superconductor, 1/T1T develops a Hebel-Slichter-like peak around TBKT, originating from the emergence of coherence peaks in the density of states, while no peak appears at the pair formation scale TBCS. We further extend our analysis to the d-wave superconductor. Our results highlight spin-lattice relaxation rate as a sensitive tool to detect the superconducting BKT transition and open routes to exploring its manifestation in unconventional pairing states.
@article{arxiv.2511.13486,
title = {Spin-Lattice Relaxation in Two-Dimensional Superconducting BKT Transition},
author = {Wei-Wei Yang and Shao-Hang Shi and Zongsheng Zhou and Zi-Xiang Li and Kun Jiang and Jiangping Hu},
journal= {arXiv preprint arXiv:2511.13486},
year = {2026}
}