Revealing charge-tunneling processes between a quantum dot and a superconducting island through gate sensing

Revealing charge-tunneling processes between a quantum dot and a superconducting island through gate sensing

van Veen, J. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
de Jong, D. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Han, L. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Prosko, C.G. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Krogstrup, P. (University of Copenhagen)
Watson, J.D. (TU Delft QRD/Kouwenhoven Lab; Microsoft Quantum Lab Delft)
Kouwenhoven, Leo P. (TU Delft QRD/Kouwenhoven Lab; TU Delft QN/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft; Microsoft Quantum Lab Delft)
Pfaff, W. (TU Delft QRD/Kouwenhoven Lab; Microsoft Quantum Lab Delft)

2019

We report direct detection of charge tunneling between a quantum dot and a superconducting island through radio-frequency gate sensing. We are able to resolve spin-dependent quasiparticle tunneling as well as two-particle tunneling involving Cooper pairs. The quantum dot can act as an RF-only sensor to characterize the superconductor addition spectrum, enabling us to access subgap states without transport. Our results provide guidance for future dispersive parity measurements of Majorana modes, which can be realized by detecting the parity-dependent tunneling between dots and islands.

http://resolver.tudelft.nl/uuid:b5642076-5913-425c-963c-c1c8c48b169e

https://doi.org/10.1103/PhysRevB.100.174508

2469-9950

Physical Review B, 100 (17)

Institutional Repository

journal article

© 2019 J. van Veen, D. de Jong, L. Han, C.G. Prosko, P. Krogstrup, J.D. Watson, Leo P. Kouwenhoven, W. Pfaff