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Quantized critical supercurrent in SrTiO3-based quantum point contacts
Evgeny Mikheev1,2, Ilan T Rosen2,3, David Goldhaber-Gordon1,2
1Department of Physics, Stanford University, Stanford, CA 94305, USA.
Science Advances
|October 1, 2021
Summary
Researchers created superconducting quantum point contacts using only strontium titanate (SrTiO3). This breakthrough enables electrostatic control over superconductivity, paving the way for novel mesoscopic and topological superconducting devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Superconductivity in strontium titanate (SrTiO3) is observed at low carrier densities, allowing for electrostatic control, unlike conventional superconductors.
- Developing single-material platforms for mesoscopic superconducting experiments is crucial for advancing quantum technologies.
Purpose of the Study:
- To demonstrate nanoscale weak links within a single SrTiO3 material for superconducting transport studies.
- To engineer superconducting quantum point contacts and investigate their properties using electrostatic gating.
Main Methods:
- Fabrication of nanoscale weak links connecting superconducting leads, all composed of SrTiO3.
- Utilizing ionic liquid gating to accumulate carriers in the SrTiO3 leads.
- Employing local electrostatic gates to precisely control the weak link's conductivity.
Main Results:
- Successful creation of devices behaving as superconducting quantum point contacts.
- Observation of a quantized critical supercurrent in the fabricated SrTiO3 weak links.
- Demonstration of electrostatic control over superconductivity at the nanoscale.
Conclusions:
- Strontium titanate (SrTiO3) can serve as a versatile single-material platform for mesoscopic superconducting experiments.
- These findings represent a significant step towards engineering topological superconductivity within SrTiO3-based devices.
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