2e-periodic Switching Current Modulation in Nanowire Single Cooper Pair Transistors

ORAL

Abstract

Over the past years, many studies have reported on signatures of Majorana modes via zero-bias peaks. However, to date there have been no experiments demonstrating their non-Abelian statistics. Recently, Aasen et al. proposed that the Majorana fusion channels, intimately related to their non-Abelian statistics, could be probed in a single-wire geometry [1]. An outstanding issue for the fusion experiment, however, is quasiparticle poisoning, because it can lead to decoherence and readout errors.

Therefore, we studied parity effects in gate-tuneable single Cooper pair transistors made from proximitized InAs nanowires. We measured the gate modulation of the switching currents as a function of temperature, island length, and the magnetic field applied parallel to the wire. We observed 2e-periodic signals for a wide range of gate settings. This implies there are few deep quasiparticle traps present in the island. We develop a thermodynamic model, which shows that our island does experience rapid parity fluctuations despite this clean 2e signal. When increasing the magnetic field, an oscillating even-odd pattern appears. We attribute this to the zero-energy crossing of an Andreev bound state.

References:
[1] D. Aasen et al. PRX 6, 031016 (2016)

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Presenters

  • Jasper Van Veen

    QuTech and Kavli Institute of NanoScience, Delft University of Technology

Authors

  • Jasper Van Veen

    QuTech and Kavli Institute of NanoScience, Delft University of Technology

  • Alex Proutski

    QuTech and Kavli Institute of NanoScience, Delft University of Technology

  • Dmitry Pikulin

    Station-Q, Microsoft Research, Station Q, Microsoft Research, Microsoft Corp, Station Q, Microsoft Corp

  • Torsten Karzig

    Station-Q, Microsoft Research, Microsoft Corp

  • Roman Lutchyn

    Microsoft Station Q, Station-Q, Microsoft Research, Station Q, Microsoft Corp

  • Peter Krogstrup

    Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Center for Quantum Devices and Station-Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, University of Copenhagen

  • Jesper Nygard

    Center for quantum devices, Niels Bohr Institute, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Center for Quantum Devices and Station-Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center of Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen

  • Attila Geresdi

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft Univ of Tech, QuTech and Kavli Institute of NanoScience, Delft University of Technology

  • Leo Kouwenhoven

    Microsoft Station-Q Delft, Delft University of Technology, Delft Univ of Tech, Qutech and Kavli Institute of Nanoscience and Microsoft Station Q Delft, Delft University of Technology, QuTech, Kavli Institute of Nanoscience, Station Q at Delft University of Technology, Delft University of Technology, Microsoft Station-Q at Delft University of Technology, Delft Univ. of Technology, Microsoft Station Q, Station Q Delft, Microsoft, Microsoft Station Q

  • John Watson

    Microsoft Station-Q at Delft University of Technology, Purdue University