Vortex dynamics in the two-dimensional BCS-BEC crossover
Abstract
The Bardeen-Cooper-Schrieffer (BCS) condensation and Bose-Einstein condensation (BEC) are the two limiting ground states of paired Fermion systems, and the crossover between these two limits has been a source of excitement for both fields of high temperature superconductivity and cold atom superfluidity. For superconductors, ultra-low doping systems like graphene and LixZrNCl successfully approached the crossover starting from the BCS-side. These superconductors offer new opportunities to clarify the nature of charged-particles transport towards the BEC regime. Here we report the study of vortex dynamics within the crossover using their Hall effect as a probe in LixZrNCl. We observed a systematic enhancement of the Hall angle towards the BCS-BEC crossover, which was qualitatively reproduced by the phenomenological time-dependent Ginzburg-Landau (TDGL) theory. LixZrNCl exhibits a band structure free from various electronic instabilities, allowing us to achieve a comprehensive understanding of the vortex Hall effect and thereby propose a global picture of vortex dynamics within the crossover. These results demonstrate that gate-controlled superconductors are ideal platforms towards investigations of unexplored properties in BEC superconductors.
Cite
@article{arxiv.2209.04940,
title = {Vortex dynamics in the two-dimensional BCS-BEC crossover},
author = {Max Heyl and Kyosuke Adachi and Yuki M. Itahashi and Yuji Nakagawa and Yuichi Kasahara and Emil J. W. List-Kratochvil and Yusuke Kato and Yoshihiro Iwasa},
journal= {arXiv preprint arXiv:2209.04940},
year = {2022}
}