@article{bibcite_91,
  author = {Teresa Brecht and Yiwen Chu and Christopher Axline and Wolfgang Pfaff and Jacob Blumoff and Kevin Chou and Lev Krayzman and Luigi Frunzio and Robert Schoelkopf},
  title = {Micromachined integrated quantum circuit containing a superconducting qubit},
  abstract = {<p>We present a device demonstrating a lithographically patterned transmon integrated with a micromachined cavity resonator. Our two-cavity, one-qubit device is a multilayer microwave-integrated quantum circuit (MMIQC), comprising a basic unit capable of performing circuit-QED operations. We describe the qubit-cavity coupling mechanism of a specialized geometry using an electric-field picture and a circuit model, and obtain specific system parameters using simulations. Fabrication of the MMIQC includes lithography, etching, and metallic bonding of silicon wafers. Superconducting wafer bonding is a critical capability that is demonstrated by a micromachined storage-cavity lifetime of 34.3  𝜇⁢s, corresponding to a quality factor of 2{\texttimes}106 at single-photon energies. The transmon coherence times are 𝑇<sub>1</sub>=6.4  𝜇⁢s, and 𝑇<sub>2</sub><sup>echo</sup>=11.7  𝜇⁢s. We measure qubit-cavity dispersive coupling with a rate 𝜒<sub>𝑞⁢𝜇</sub>/2⁢𝜋=-1.17  MHz, constituting a Jaynes-Cummings system with an interaction strength 𝑔/2⁢𝜋=49  MHz. With these parameters we are able to demonstrate circuit-QED operations in the strong dispersive regime with ease. Finally, we highlight several improvements and anticipated extensions of the technology to complex MMIQCs.</p>},
  year = {2017},
  journal = {Physical Review Applied},
  volume = {7},
  number = {4},
  pages = {044018},
  publisher = {APS},
  doi = {10.1103/physrevapplied.7.044018},
}