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arXiv · 2110.11535

Clean ballistic quantum point contact in SrTiO$_3$

Evgeny Mikheev·Ilan T. Rosen·Marc A. Kastner·David Goldhaber-Gordon
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Abstract

Two dimensional electron gases based on SrTiO$_3$ 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 SrTiO$_3$ nanostructures have been complicated by disorder. Here we introduce a facile approach to achieving high mobility and patterning gate-tunable structures in SrTiO$_3$, 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.

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Evgeny Mikheev, Ilan T. Rosen, Marc A. Kastner, David Goldhaber-Gordon. 2021-10-22. Clean ballistic quantum point contact in SrTiO$_3$. https://arxiv.org/abs/2110.11535

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