Dynamics and manipulation of a trapped, superconducting quasiparticle: Part 1/2

ORAL

Abstract

The physics of conventional and exotic superconductors can be probed through their microscopic quasiparticle excitations. Recent advances in mesoscopic superconductor-semiconductor devices have created the opportunity to measure and control such excitations, such as Majorana zero modes in a topological superconductor regime. Here, our mesoscopic device is a Josephson element with an InAs nanowire weak link. Due to spin-orbit coupling in the nanowire, the spin states of a single quasiparticle trapped in the junction’s Andreev levels exhibit microwave-accessible energy splittings without an applied magnetic (Zeeman) field. This “superconducting spin” is readily coupled to a microwave resonator via its spin-dependent supercurrent. We will present our experimental platform demonstrating large spin-dependent dispersive shifts of a microwave resonator. We achieve single-shot, quantum-non-demolition readout of the spin as well as coherent manipulation of the quasiparticle state. We will discuss the real-time dynamics of the quasiparticle, which have implications for Majorana devices and Andreev spin qubits. In this first part of a joint presentation, we will present the background, experimental setup, and a theoretical model for our system.

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Presenters

  • Valla Fatemi

    Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale University

Authors

  • Valla Fatemi

    Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale University

  • Max Hays

    Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale University

  • Daniël Bouman

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology

  • Kyle Serniak

    MIT Lincoln Lab, Yale University, MIT Lincoln Laboratory, Applied Physics, Yale University

  • Spencer Diamond

    Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale University

  • Tom Connolly

    Applied Physics, Yale University

  • Gijs De Lange

    Microsoft Quantum Lab Delft, 2628 CJ, Delft, The Netherlands, Quantum Lab Delft, Microsoft, Applied Physics, Yale University, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Microsoft Corp

  • Peter Krogstrup

    Niels Bohr Institute, University of Copenhagen, University of Copenhagen, Center for Quantum Devices and Microsoft Quantum Lab--Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen

  • Jesper Nygård

    Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, University of Copenhagen

  • Attila Geresdi

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Department of Microtechnology and Nanoscience, Chalmers University of Technology

  • Michel H. Devoret

    Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale University