Despite its relatively low critical temperature Tc = 1.6 K, the superconducting state of uranium ditelluride survives to magnetic fields as high as 34.6 T (for field applied along the hard magnetization axis). At this field however, the superconducting state suddenly collapses. The cause of this collapse has remained elusive so far. Combining Hall effect and thermoelectric power measurements at high magnetic field, a recent study shows that the electronic band structure changes drastically at 34.6 T. This Fermi surface reconstruction causes a drop in the number of charge carriers in the system. Superconductivity results from interactions between those charge carriers. The fundamental change in the electronic structure found here might cause of the collapse of superconductivity.
Publication - Evidence of Fermi surface reconstruction at the metamagnetic transition of the strongly correlated superconductor UTe2
Q. Niu, G. Knebel, D. Braithwaite, D. Aoki, G. Lapertot, M. Vališka, G. Seyfarth, W. Knafo, T. Helm, J.-P. Brison, J. Flouquet, and A. Pourret, Phys. Rev. Research 2, 033179 (2020)
Figure – Thermoelectric power S of UTe2 for magnetic field between 0 and 36 T applied along the b-axis of the crystallographic structure. A clear anomaly at H =34.6 T is resolved, providing evidence for the Fermi surface reconstruction.