Fortifying the strong-coupling regime of quantum dot circuit QED using high-impedance superconducting resonators

ORAL

Abstract

In quantum dot cQED, the spin-photon coupling rate gs is proportional to the charge-photon coupling rate gc. To move deeper into the strong coupling regime, gc can be enhanced through the use of high kinetic inductance films. We report direct current resistivity measurements and microwave investigations of niobium nitride (NbN) films of different thicknesses. Consistent with expectations, the kinetic inductance increases rapidly as the film thickness is decreased below 50 nm. For 15 nm NbN thin films, we measured a large kinetic inductance of LK ∼ 41.2 pH/sq and sheet resistance of RS ~ 274 Ohm/sq. We investigate the use of these films in the fabrication of high impedance half-wavelength microwave cavities.

*Research sponsored by Army Research Office grant W911NF-15-1-0149. Devices were fabricated in the Princeton University Quantum Device Nanofabrication Laboratory.

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Presenters

  • Xuanzi Zhang

    • Department of Physics, Princeton University
    • Princeton University

Authors

  • Xuanzi Zhang

    • Department of Physics, Princeton University
    • Princeton University

  • Zheyi Zhu

    • Princeton University

  • Phuan Ong

    • Princeton University
    • Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

  • Jason R Petta

    • Princeton University
    • Department of Physics, Princeton University