Self-reconstruction of order parameter in spin-triplet superconductor UTe$_2$
Y. Tokiwa, P. Opletal, H. Sakai, K. Kubo, S. Kambe, E. Yamamoto, M. Kimata, S. Awaji, T. Sasaki, D. Aoki, Y. Yanase, Y. Tokunaga, Y. Haga
公開日: 2022/10/21
Abstract
We investigate the effect of easy-axis metamagnetic crossover on superconductivity in UTe$_2$ along the $a$-axis through measurements of AC susceptibility, magnetization, and the magnetocaloric effect. In ultra-clean single crystals, we identify a field-induced phase transition within the superconducting state at 5.6 T, driven by metamagnetism. This transition leads to a high-field superconducting state, significantly increasing the upper critical field to 12 T. A sudden increase in entropy at the transition suggests a self-reconstruction of the order parameter, enabling multi-component superconducting states to adapt to external perturbations.