Symmetry of magnetic correlations in spin-triplet superconductor UTe2

TL;DR

This study investigates magnetic excitations in the spin-triplet superconductor UTe2, revealing their relation to Kondo lattice behavior and how superconductivity modifies these magnetic correlations.

Contribution

It provides the first detailed analysis of magnetic excitations in UTe2 across normal and superconducting states using inelastic neutron scattering.

Findings

Magnetic excitations follow interband correlations in a Kondo lattice.

Superconductivity causes noticeable changes in magnetic excitations.

Magnetic correlations are not solely due to ferromagnetic or antiferromagnetic dominance.

Abstract

The temperature dependence of the low-energy magnetic excitations in the spin-triplet superconductor UTe$_2$ was measured via inelastic neutron scattering in the normal and superconducting states. The imaginary part of the dynamic susceptibility follows the behavior of interband correlations in a hybridized Kondo lattice with an appropriate characteristic energy. These excitations are a lower-dimensional analogue of phenomena observed in other Kondo lattice materials, such that their presence is not necessarily due to dominance of ferromagnetic or antiferromagnetic correlations. The onset of superconductivity alters the magnetic excitations noticeably on the same energy scales, suggesting that these changes originate from additional electronic structure modification.