Two dimensional electron gases based on SrTiO3 are an intriguing platform for exploring mesoscopic superconductivity combined with spin-orbit coupling, offering electrostatic tunability from insulator to metal to superconductor within a single material. So far, however, quantum effects in SrTiO3 nanostructures have been complicated by disorder. Here we introduce a facile approach to achieving high mobility and patterning gate-tunable structures in SrTiO3, and use it to demonstrate ballistic constrictions with clean normal state conductance quantization. Conductance plateaus show two-fold degeneracy that persists to magnetic fields of at least 5 T - far beyond what one would expect from the g-factor extracted at high fields - a potential signature of electron pairing extending outside the superconducting regime.
@article{arxiv.2110.11535,
title = {Clean ballistic quantum point contact in SrTiO$_3$},
author = {Evgeny Mikheev and Ilan T. Rosen and Marc A. Kastner and David Goldhaber-Gordon},
journal= {arXiv preprint arXiv:2110.11535},
year = {2021}
}