Physics Special Seminar with J. C. Seamus Davis on Quasiparticle Interference Imaging of Andreev Surface Bands in UTe2

Superconductivity occurs in metals when pairs of electrons having opposite momenta ±k interact via a momentum-dependent electron pairing potential Δ_k which binds them into Cooper pairs. Modern topological categorization of superconductors is based on the topologically non-trivial properties of this electron-pair potential Δ_k and is of profound fundamental significance. Indeed, intrinsic topological superconductors (ITS) represent a unique and quite extraordinary type of macroscopic quantum matter, promising both fundamental new physics and revolutionary technology.  Although sought for many decades ITS remain highly elusive as of 2024. Neither the odd-parity electron-pairing potential Δ_k, nor the electronic structure k_σ (E) of any superconductive topological surface band TSB, nor any surface chiral supercurrents v(r) have yet been demonstrated for any superconductive material whatsoever. Here, we explore all these characteristics in UTe2, a leading candidate ITS, by introducing a suite of unique new superconductive-tip STM techniques and instruments.

This lecture was made possible by the William C. Ferguson fund.