STM studies of the heavyfermion superconductor UTe2
Spin-tripletsuperconductivity is a condensate of electron pairs with spin-1 and anodd-parity wavefunction. A particularly interesting manifestation of tripletpairing is a chiral p-wave state which is topologically non-trivial and anatural platform for realizing Majorana edge modes. Triplet pairing is however rare in solidstate systems. The best-known example of chiral spin-triplet paring is thesuperfluid 3He-A phase and over the last few decades, there has beenan intensive search for potential spin-triplet superconductors in solid-statesystems. Since pairing is most naturally mediated by ferromagnetic spinfluctuations, uranium based heavy fermion systems containing f-electron elements that can harbor bothstrong correlations and magnetism are considered ideal candidate spin-tripletsuperconductors. In this work I will present scanning tunneling microscopy(STM) data on the newly discovered heavy fermion superconductor, UTe2with a TSC of 1.6 K. I will show signatures of coexistingKondo effect and superconductivity which show competing spatial modulationswithin one unit-cell. STM spectroscopyat step edges show signatures of chiral in-gap states, predicted to exist at the boundaries of a topologicalsuperconductor. Finally, I will discuss signatures of other co-existing phasesin this complex superconductor.