Micromachined Integrated Quantum Circuit Containing a Superconducting Qubit

T. Brecht, Y. Chu, C. Axline, W. Pfaff, J. Z. Blumoff, K. Chou, L. Krayzman, L. Frunzio, R. J. Schoelkopf

Research output: Contribution to journalArticlepeer-review


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 μs, corresponding to a quality factor of 2×106 at single-photon energies. The transmon coherence times are T1=6.4 μs, and T2echo=11.7 μs. We measure qubit-cavity dispersive coupling with a rate χqμ/2π=-1.17 MHz, constituting a Jaynes-Cummings system with an interaction strength g/2π=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.

Original languageEnglish (US)
Article number044018
JournalPhysical Review Applied
Issue number4
StatePublished - Apr 19 2017
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


Dive into the research topics of 'Micromachined Integrated Quantum Circuit Containing a Superconducting Qubit'. Together they form a unique fingerprint.

Cite this