Amplitude and frequency sensing of microwave fields with a superconducting transmon qudit

Kristen, M. et al. (2020) Amplitude and frequency sensing of microwave fields with a superconducting transmon qudit. npj Quantum Information, 6, 57. (doi: 10.1038/s41534-020-00287-w)

Abstract

Experiments with superconducting circuits require careful calibration of the applied pulses and fields over a large frequency range. This remains an ongoing challenge as commercial semiconductor electronics are not able to probe signals arriving at the chip due to its cryogenic environment. Here, we demonstrate how the on-chip amplitude and frequency of a microwave signal can be inferred from the ac Stark shifts of higher transmon levels. In our time-resolved measurements we employ Ramsey fringes, allowing us to detect the amplitude of the systems transfer function over a range of several hundreds of MHz with an energy sensitivity on the order of 10−4. Combined with similar measurements for the phase of the transfer function, our sensing method can facilitate pulse correction for high fidelity quantum gates in superconducting circuits. Additionally, the potential to characterize arbitrary microwave fields promotes applications in related areas of research, such as quantum optics or hybrid microwave systems including photonic, mechanical or magnonic subsystems.

• Item Type: Articles
• Additional Information: This work was supported by the European Research Council (ERC) under the Grant Agreement No. 648011, Deutsche Forschungsgemeinschaft (DFG) projects INST 121384/138-1FUGG and WE 4359-7, the Initiative and Networking Fund of the Helmholtz Association, and the state of Baden-Württemberg through bwHPC. A.Sch. acknowledges financial support by the Carl-Zeiss-Foundation, A. St. by the Landesgraduiertenförderung (LGF) of the federal state Baden-Württemberg and T.W. by the Helmholtz International Research School for Teratronics (HIRST). A.V.U. acknowledges partial support from the Ministry of Education and Science of the Russian Federation in the framework of Contracts No. K2-2016-063 and No. K2-2017-081.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Weides, Professor Martin and Danilin, Dr Sergey
• Authors: Kristen, M., Schneider, A., Stehli, A., Wolz, T., Danilin, S., Ku, H.S., Long, J., Wu, X., Lake, R., Pappas, D.P., Ustinov, A.V., and Weides, M.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Quantum Circuits Group
• Journal Name: npj Quantum Information
• Publisher: Nature Research
• ISSN: 2056-6387
• ISSN (Online): 2056-6387
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in npj Quantum Information 6: 57
• Publisher Policy: Reproduced under a Creative Commons License