Scientific article

Quantum interference in an interfacial superconductor

Published inNature nanotechnology, vol. 11, no. 10, p. 861-865
Publication date2016-07-11
First online date2016-07-11

The two-dimensional superconductor formed at the interface between the complex oxides, lanthanum aluminate (LAO) and strontium titanate (STO) [1] has several intriguing properties [2–6] that set it apart from conventional superconductors. Most notably, an electric field can be used to tune its critical temperature (Tc) [7], revealing a dome-shaped phase diagram reminiscent of high Tc superconductors [8]. So far, experiments with oxide interfaces have measured quantities which probe only the magnitude of the superconducting order parameter and are not sensitive to its phase. Here, we perform phase-sensitive measurements by realizing the first superconducting quantum interference devices (SQUIDs) at the LAO/STO interface. Furthermore, we develop a new paradigm for the creation of superconducting circuit elements, where local gates enable insitu creation and control of Josephson junctions. These gate-defined SQUIDs are unique in that the entire device is made from a single superconductor with purely electrostatic interfaces between the superconducting reservoir and the weak link. We complement our experiments with numerical simulations and show that the low superfluid density of this interfacial superconductor results in a large, gate-controllable kinetic inductance of the SQUID. Our observation of robust quantum interference opens up a new pathway to understand the nature of superconductivity at oxide interfaces.

Affiliation Not a UNIGE publication
Research group
Citation (ISO format)
GOSWAMI, Srijit et al. Quantum interference in an interfacial superconductor. In: Nature nanotechnology, 2016, vol. 11, n° 10, p. 861–865. doi: 10.1038/nnano.2016.112
Main files (1)
Article (Submitted version)
ISSN of the journal1748-3387

Technical informations

Creation03/07/2022 1:35:00 PM
First validation03/07/2022 1:35:00 PM
Update time03/16/2023 2:48:18 AM
Status update03/16/2023 2:48:17 AM
Last indexation05/06/2024 10:19:33 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack