The orthorhombic uranium dichalcogenide UTe2 displays superconductivity below 1.7 K, with the anomalous feature of retaining 50% of normal state (ungapped) carriers, according to heat capacity data from two groups. Incoherent transport that crosses over from above 50 K toward a low temperature, Kondo lattice Fermi liquid regime indicates strong magnetic fluctuations and the need to include correlation effects in theoretical modeling. We report density functional theory plus Hubbard U (DFT+U) results for UTe2 to provide a platform for modeling its unusual behavior, focusing on ferromagnetic (FM, time reversal breaking) long range correlations along the a^ axis as established by magnetization measurements and confirmed by our calculations. States near the Fermi level are dominated by the j=25 configuration, with the jz=±21 sectors being effectively degenerate and half-filled. Unlike the small-gap insulating nonmagnetic electronic spectrum, the FM Fermi surfaces are large (strongly metallic) and display low dimensional features, reminiscent of the FM superconductor UGe2.
@article{arxiv.1908.01558,
title = {Spin-Orbit Coupling Induced Degeneracy in the Anisotropic Unconventional Superconductor UTe$_2$},
author = {Alexander B. Shick and Warren E. Pickett},
journal= {arXiv preprint arXiv:1908.01558},
year = {2019}
}