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High kinetic inductance superconducting cavity for strong coupling of Si/SiGe qubits

ORAL

Abstract

Achieving long range coherent interactions between qubits is a milestone of quantum information. In recent years the field of circuit quantum electrodynamics (cQED) has demonstrated long range coupling between superconducting qubits, quantum dots in various semiconductors systems, and even coupling between hybrid systems. Strong coupling between remote qubits requires that the coupling strength be larger than the decoherence rates of both the microwave cavity and the qubits. The coupling can be enhanced by increasing the impedance of the cavity. There are two possible ways to achieve such a goal: first, by using a superconductor with high kinetic inductance; second, by using an array of Josephson junctions, which constrains the application of an external magnetic field. We present a Si/SiGe quantum dot device that combines a high impedance cavity and low impedance leads to reduce the photon leakage through the DC lines. The resonator is made of NbN, a high kinetic inductance superconductor, while the leads are composed of a thin layer of NbN with a thicker layer of Nb on top to reduce the impedance of the leads. The third harmonic can be used to further enhance the coupling strength between the dots and the resonator, which is important for strong coupling.

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Presenters

  • Mario Palma

    Department of Physics, University of Wisconsin-Madison, Madison WI, USA

Authors

  • Mario Palma

    Department of Physics, University of Wisconsin-Madison, Madison WI, USA

  • Nathan Holman

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA

  • Samuel Neyens

    Department of Physics, University of Wisconsin-Madison, Madison WI, USA, University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA

  • Evan R MacQuarrie

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA

  • Lisa F Edge

    HRL, HRL laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265, USA, HRL Laboratories, HRL Laboratories LLC, 3011 Malibu Canyon Road, Malibu, California 90265, USA, HRL Laboratories, LLC

  • Mark G Friesen

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, University of Wisconsin-Madison

  • Susan Nan Coppersmith

    University of Wisconsin - Madison, University of New South Wales, Sydney, Australia, Department of Physics, University of Wisconsin-Madison, University of Wisconsin-Madison, University of New South Wales, University of Wisconsin-Madison, The University of New South Wales

  • Robert F McDermott

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, Physics, University of Wiconsin - Madison

  • Mark Alan Eriksson

    University of Wisconsin - Madison, Physics, University of Wisconsin - Madison, Madison, WI USA, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA, University of Wisconsin-Madison