Low-dimensional antiferromagnetic fluctuations in the heavy-fermion paramagnetic ladder compound UTe

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

Inelastic-neutron-scattering measurements were performed on a single crystal of the heavy-fermion paramagnet UTe above its superconducting temperature. We confirm the presence of antiferromagnetic fluctuations with the incommensurate wave-vector = (0, 0.57, 0). A quasielastic signal is found, whose momentum-transfer dependence is compatible with fluctuations of magnetic moments , with a sine-wave modulation of wave-vector and in-phase moments on the nearest U atoms. Low dimensionality of the magnetic fluctuations, consequence of the ladder structure, is indicated by weak correlations along the direction . These results constitute constraints for models of magnetically-mediated superconductivity in UTe.