  UTe2 is a newly-discovered unconventional superconductor wherein
multicomponent topological superconductivity is anticipated based on the
presence of two superconducting transitions and time-reversal symmetry breaking
in the superconducting state. The observation of two superconducting
transitions, however, remains controversial. Here we demonstrate that UTe2
single crystals displaying an optimal superconducting transition temperature at
2 K exhibit a single transition and remarkably high quality supported by their
small residual heat capacity in the superconducting state and large residual
resistance ratio. Our results shed light on the intrinsic superconducting
properties of UTe2 and bring into question whether UTe2 is a multicomponent
superconductor at ambient pressure.
