Demonstration of superconducting micromachined cavities

Journal Article · Mon Nov 09 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4935541· OSTI ID:22486055

Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. ^[1]

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1. Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

• OSTI ID: 22486055
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
APERTURES
INDIUM
MICROWAVE RADIATION
QUALITY FACTOR
QUANTUM COMPUTERS
QUANTUM ELECTRODYNAMICS
QUBITS
SUPERCONDUCTING CAVITY RESONATORS