Rapid Detection of Coherent Tunneling in an InAs Nanowire Quantum Dot through Dispersive Gate Sensing

Journal Article (2019)
Author(s)

D. De Jong (TU Delft - QuTech Advanced Research Centre, TU Delft - QRD/Kouwenhoven Lab)

Jasper van Veen (TU Delft - QRD/Kouwenhoven Lab, TU Delft - QuTech Advanced Research Centre)

Luca Binci (TU Delft - QRD/Kouwenhoven Lab, TU Delft - QuTech Advanced Research Centre)

A. Singh (TU Delft - QRD/Kouwenhoven Lab, TU Delft - QuTech Advanced Research Centre)

P. Krogstrup (University of Copenhagen)

Leo Kouwenhoven (TU Delft - QRD/Kouwenhoven Lab, TU Delft - QuTech Advanced Research Centre, Microsoft Quantum Lab Delft, TU Delft - QN/Kouwenhoven Lab)

W Pfaff (TU Delft - QRD/Kouwenhoven Lab, Microsoft Quantum Lab Delft)

J. D. Watson (Microsoft Quantum Lab Delft, TU Delft - QRD/Kouwenhoven Lab)

Research Group
QRD/Kouwenhoven Lab
Copyright
© 2019 D. de Jong, J. van Veen, L. Binci, A. Singh, P. Krogstrup, Leo P. Kouwenhoven, W. Pfaff, J.D. Watson
DOI related publication
https://doi.org/10.1103/PhysRevApplied.11.044061
More Info
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Publication Year
2019
Language
English
Copyright
© 2019 D. de Jong, J. van Veen, L. Binci, A. Singh, P. Krogstrup, Leo P. Kouwenhoven, W. Pfaff, J.D. Watson
Research Group
QRD/Kouwenhoven Lab
Issue number
4
Volume number
11
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Abstract

Dispersive sensing is a powerful technique that enables scalable and high-fidelity readout of solid-state quantum bits. In particular, gate-based dispersive sensing has been proposed as the readout mechanism for future topological qubits, which can be measured by single electrons tunneling through zero-energy modes. The development of such a readout requires resolving the coherent charge tunneling amplitude from a quantum dot in a Majorana-zero-mode host system faithfully on short time scales. Here, we demonstrate rapid single-shot detection of a coherent single-electron tunneling amplitude between InAs nanowire quantum dots. We realize a sensitive dispersive detection circuit by connecting a sub-GHz, lumped-element microwave resonator to a high-lever arm gate on one of the dots. The resulting large dot-resonator coupling leads to an observed dispersive shift that is of the order of the resonator linewidth at charge degeneracy. This shift enables us to differentiate between Coulomb blockade and resonance - corresponding to the scenarios expected for qubit-state readout - with a signal-to-noise ratio exceeding 2 for an integration time of 1μs. Our result paves the way for single-shot measurements of fermion parity on microsecond time scales in topological qubits.