2017/11/16 by Bradley A. Moores, Lucas R. Sletten, Jeremie J. Viennot +1 · 2 citations
Physics and Astronomy · #quant-ph #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.120.227701
published as Phys. Rev. Lett. 120, 227701 (2018)
arxiv created 2017/11/16 · arxiv updated 2018/06/06
We investigate an acoustical analog of circuit quantum electrodynamics that facilitates compact high-Q (>20,000) microwave-frequency cavities with dense spectra. We fabricate and characterize a device that comprises a flux tunable transmon coupled to a 300 μm long surface acoustic wave resonator. For some modes, the qubit-cavity coupling reaches 6.5 MHz, exceeding the cavity loss rate (200 kHz), qubit linewidth (1.1 MHz), and the cavity free spectral range (4.8 MHz), placing the device in both the strong coupling and strong multimode regimes. With the qubit detuned from the cavity, we show that the dispersive shift behaves according to predictions from a generalized Jaynes-Cummings Hamiltonian. Finally, we observe that the qubit linewidth strongly depends on its frequency, as expected for spontaneous emission of phonons, and we identify operating frequencies where this emission rate is suppressed.