Anomalous electromagnetic response in the spin-triplet superconductor UTe2

The recently discovered heavy-fermion superconductor UTe2, as a promising candidate for an odd-parity superconductivity, exhibits anomalous magnetic-field reinforced superconductivity with a huge upper critical field of 35 T. However, the thermodynamic properties of this unconventional superconductivity still remain unclear. Herein we present the results of dc magnetization and heat capacity measurements in UTe2 to probe the magnetic response at low temperatures. The obtained isothermal magnetization in the superconducting state of UTe2 clearly demonstrates the anomalous magnetic flux pinning effect, which is most likely related to the peculiar electromagnetic response of the spin-triplet pairing state in the hard-magnetization axis (orthorhombic b axis). The ac susceptibility measurements support the anomalous vortex states in UTe2. We also found evidence for the Lifshitz transition just above Hc2 and the anomalous flux pinning anomalies for the easy-magnetization axis (a axis).

Automated summary

This study investigates the magnetic response of UTe2 at low temperatures through dc magnetization and heat capacity measurements. The results reveal the presence of anomalous magnetic flux pinning effect in the superconducting state of UTe2, which is related to its peculiar electromagnetic response.