Concentric transmon qubit featuring fast tunability and an anisotropic magnetic dipole moment

Braumüller, J. et al. (2016) Concentric transmon qubit featuring fast tunability and an anisotropic magnetic dipole moment. Applied Physics Letters, 108(3), 032601. (doi: 10.1063/1.4940230)

Abstract

We present a planar qubit design based on a superconducting circuit that we call concentric transmon. While employing a straightforward fabrication process using Al evaporation and lift-off lithography, we observe qubit lifetimes and coherence times in the order of 10 μs10 μs. We systematically characterize loss channels such as incoherent dielectric loss, Purcell decay and radiative losses. The implementation of a gradiometric SQUID loop allows for a fast tuning of the qubit transition frequency and therefore for full tomographic control of the quantum circuit. Due to the large loop size, the presented qubit architecture features a strongly increased magnetic dipole moment as compared to conventional transmon designs. This renders the concentric transmon a promising candidate to establish a site-selective passive direct ẐẐ coupling between neighboring qubits, being a pending quest in the field of quantum simulation.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Weides, Professor Martin
• Authors: Braumüller, J., Sandberg, M., Vissers, M. R., Schneider, A., Schlör, S., Grünhaupt, L., Rotzinger, H., Marthaler, M., Lukashenko, A., Dieter, A., Ustinov, A. V., 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: 21 January 2016
• Copyright Holders: Copyright © 2016 AIP Publishing LLC
• First Published: First published in Applied Physics Letters 108(3): 032601
• Publisher Policy: Reproduced in accordance with the publisher copyright policy