Event

The spin-triplet superconductor UTe2 has recently emerged as a rich system that incorporates aspects
of unconventional superconductivity, heavy-electron physics and non-trivial topologies.
Superconductivity in UTe2 is characterized by enormous upper critical fields that exceed the
paramagnetic limit and re-enter in ultra-high fields, nodal quasiparticle excitations, chiral in-gap
surface states, and multiple distinct superconducting phases that span regimes of temperature,
magnetic field and applied pressure. Superconductivity emerges from a renormalized electronic
structure of hybridized f-electrons which give rise to archetypal heavy fermion features such as an
enhanced quasiparticle heat capacity and hybridization gap, yet key questions about the nature of
magnetism, electronic structure, order instabilities and sample dependence remain. In particular,
recent advances in crystal quality have been achieved by varying synthesis methods - including
variations in techniques, composition and even temperature ranges used for growth - to enable
enhancements in conductivity, transition temperature and ability to measure quantum oscillations. This
talk will review the evolution of sample variations and resultant physical properties of UTe2 that shed
light on the nature of superconductivity in different parameter regimes of temperature, pressure and
magnetic fields.