Field-induced compensation of magnetic exchange as the possible origin of reentrant superconductivity in UTe.

The potential spin-triplet heavy-fermion superconductor UTe exhibits signatures of multiple distinct superconducting phases. For field aligned along the b axis, a metamagnetic transition occurs at μH ≈ 35 T. It is associated with magnetic fluctuations that may be beneficial for the field-reinforced superconductivity surviving up to H.

Quantum-well states at the surface of a heavy-fermion superconductor.

Two-dimensional electronic states at surfaces are often observed in simple wide-band metals such as Cu or Ag (refs. ). Confinement by closed geometries at the nanometre scale, such as surface terraces, leads to quantized energy levels formed from the surface band, in stark contrast to the continuous energy dependence of bulk electron bands.

Unconventional superconductivity in UTe.

The novel spin-triplet superconductor candidate UTewas discovered only recently at the end of 2018 and already attracted enormous attention. We review key experimental and theoretical progress which has been achieved in different laboratories. UTeis a heavy-fermion paramagnet, but following the discovery of superconductivity, it has been expected to be close to a ferromagnetic instability, showing many similarities to the U-based ferromagnetic superconductors, URhGe and UCoGe.

Probing insulators under pressure.

Applying pressure on a material can reveal many physical properties and is a very efficient tool to understand its physics. Resistivity measurements have been the ideal probe to study metals under pressure. However, in the case of insulators, resistivity, or conductivity, it is often not the appropriate quantity characterizing the material.

Fermi-Surface Instability in the Heavy-Fermion Superconductor UTe_{2}.

Transport measurements are presented up to fields of 29 T in the recently discovered heavy-fermion superconductor UTe_{2} with magnetic field H applied along the easy magnetization a axis of the body-centered orthorhombic structure. The thermoelectric power varies linearly with temperature above the superconducting transition, T_{SC}=1.5  K, indicating that superconductivity develops in a Fermi liquid regime.