Josephson φ0-junction in nanowire quantum dots

Journal article (2016)

Authors

D.B. Szombati QRD/Kouwenhoven Lab - QuTech Advanced Research Centre
S. Nadj-Perge QN/Quantum Transport
D. Car Eindhoven University of Technology
S. R. Plissard Université de Toulouse
E.P.A.M. Bakkers QN/Bakkers Lab , Eindhoven University of Technology
Leo P. Kouwenhoven QRD/Kouwenhoven Lab - QuTech Advanced Research Centre
Research Group
QRD/Kouwenhoven Lab (QuTech Advanced Research Centre) (TU Delft)
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Published Date

2016

Language

English

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Faculty

QuTech Advanced Research Centre

Department

Qubit Research Division

Research Group

QRD/Kouwenhoven Lab

Abstract

The Josephson effect describes supercurrent flowing through a junction connecting two superconducting leads by a thin barrier. This current is driven by a superconducting phase difference φbetween the leads. In the presence of chiral and time-reversal symmetry of the Cooper pair tunnelling process, the current is strictly zero when φvanishes. Only if these underlying symmetries are broken can the supercurrent for φ= 0 be finite. This corresponds to a ground state of the junction being offset by a phase φ0, different from 0 or π. Here, we report such a Josephson φ0 -junction based on a nanowire quantum dot. We use a quantum interferometer device to investigate phase offsets and demonstrate that φ0 can be controlled by electrostatic gating. Our results may have far-reaching implications for superconducting flux- and phase-defined quantum bits as well as for exploring topological superconductivity in quantum dot systems.