Radiation-suppressed superconducting quantum bit in a planar geometry

Sandberg, M., Vissers, M. R., Ohki, T. A., Gao, J., Aumentado, J., Weides, M. and Pappas, D. P. (2013) Radiation-suppressed superconducting quantum bit in a planar geometry. Applied Physics Letters, 102(7), 072601. (doi: 10.1063/1.4792698)

Abstract

We present a superconducting transmon qubit circuit design based on large, coplanar capacitor plates and a microstrip resonator. The microstrip geometry, with the ground plane on the back, enhances access to the circuit for state preparation and measurement relative to other designs. The device is fabricated on a silicon substrate using low loss, stoichiometric titanium nitride for the capacitor plates and a single small aluminium/aluminium-oxide/aluminium junction. We observe relaxation and coherence times of 11.7 ± 0.2 μs and 9.6 ± 0.5 μs, respectively, using spin echo. Calculations show that the close proximity of the superconducting back-plane has the added advantage of suppressing the otherwise high radiation loss of the qubit.

• Item Type: Articles
• Additional Information: This work was supported by DARPA and the NIST Quantum Information Program.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Weides, Professor Martin
• Authors: Sandberg, M., Vissers, M. R., Ohki, T. A., Gao, J., Aumentado, J., Weides, M., and Pappas, D. P.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Applied Physics Letters
• Publisher: AIP Publishing
• ISSN: 0003-6951
• ISSN (Online): 1077-3118
• Published Online: 19 February 2013