纵向自旋涨落驱动UTe₂中的场增强超导性。

Longitudinal Spin Fluctuations Driving Field-Reinforced Superconductivity in UTe_{2}.

作者信息

Tokunaga Y, Sakai H, Kambe S, Opletal P, Tokiwa Y, Haga Y, Kitagawa S, Ishida K, Aoki D, Knebel G, Lapertot G, Krämer S, Horvatić M

机构信息

ASRC, Japan Atomic Energy Agency Tokai, Ibaraki 319-1195, Japan.

Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.

出版信息

Phys Rev Lett. 2023 Dec 1;131(22):226503. doi: 10.1103/PhysRevLett.131.226503.

DOI:10.1103/PhysRevLett.131.226503

PMID:38101342

Abstract

Our measurements of ^{125}Te NMR relaxations reveal an enhancement of electronic spin fluctuations above μ_{0}H^{*}∼15 T, leading to their divergence in the vicinity of the metamagnetic transition at μ_{0}H_{m}≈35 T, below which field-reinforced superconductivity appears when a magnetic field (H) is applied along the crystallographic b axis. The NMR data evidence that these fluctuations are dominantly longitudinal, providing a key to understanding the peculiar superconducting phase diagram in H∥b, where such fluctuations enhance the pairing interactions.

摘要

我们对(^{125}Te)核磁共振弛豫的测量结果表明，在(\mu_0H^{*}\sim15) T以上，电子自旋涨落增强，导致其在(\mu_0H_m\approx35) T附近的变磁转变附近发散，在该磁场以下，当沿晶体学b轴施加磁场（H）时，会出现场增强超导性。核磁共振数据表明，这些涨落主要是纵向的，这为理解H∥b方向上特殊的超导相图提供了关键，在该相图中，这种涨落增强了配对相互作用。