Feedback of superconductivity on the magnetic excitation spectrum of UTe

UTeの磁気励起における超伝導のフィードバック

Raymond, S.*; Knafo, W.*; Knebel, G.*; 金子 耕士   ; Brison, J.-P.*; Flouquet, J.*; 青木 大*; Lapertot, G.*

Raymond, S.*; Knafo, W.*; Knebel, G.*; Kaneko, Koji; Brison, J.-P.*; Flouquet, J.*; Aoki, Dai*; Lapertot, G.*

We investigate the spin dynamics in the superconducting phase of UTe by triple-axis inelastic neutron scattering on a single crystal sample. At the wave-vector = (0, 0.57, 0), where the normal state antiferromagnetic correlations are peaked, a modification of the excitation spectrum is evidenced, on crossing the superconducting transition, with a reduction of the relaxation rate together with the development of an inelastic peak at 1 meV. The low dimensional nature and the a-axis polarization of the fluctuations, that characterise the normal state, are essentially maintained below Tsc. The high ratio of 7.2 contrasts with the most common behaviour in heavy fermion superconductors.