Quantized critical supercurrent in SrTiO<sub>3</sub>-based quantum point contacts.

Mikheev, Evgeny; Rosen, Ilan T; Goldhaber-Gordon, David · Sci Adv · 2021

basic_science · Level V

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Abstract

Superconductivity in SrTiO<sub>3</sub> occurs at remarkably low carrier densities and therefore, unlike conventional superconductors, can be controlled by electrostatic gates. Here, we demonstrate nanoscale weak links connecting superconducting leads, all within a single material, SrTiO<sub>3</sub>. Ionic liquid gating accumulates carriers in the leads, and local electrostatic gates are tuned to open the weak link. These devices behave as superconducting quantum point contacts with a quantized critical supercurrent. This is a milestone toward establishing SrTiO<sub>3</sub> as a single-material platform for mesoscopic superconducting transport experiments that also intrinsically contains the necessary ingredients to engineer topological superconductivity.