Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 2020 | Submitted + Published
Journal Article Open

Quantum frequency locking and downconversion in a driven qubit-cavity system

Abstract

We study a periodically driven qubit coupled to a quantized cavity mode. Despite its apparent simplicity, this system supports a rich variety of exotic phenomena, such as topological frequency conversion as recently discovered in Martin et al. [Phys. Rev. X 7, 041008 (2017)]. Here we report on a qualitatively different phenomenon that occurs in this platform, where the cavity mode's oscillations lock their frequency to a rational fraction r/q of the driving frequency Ω. This phenomenon, which we term quantum frequency locking, is characterized by the emergence of q-tuplets of stationary (Floquet) states whose quasienergies are separated by Ω/q, up to exponentially small corrections. The Wigner functions of these states are nearly identical, and exhibit highly regular and symmetric structure in phase space. Similarly to Floquet time crystals, these states underlie discrete time-translation symmetry breaking in the model. We develop a semiclassical approach for analyzing and predicting quantum frequency locking in the model, and use it to identify the conditions under which it occurs.

Additional Information

© 2020 The Author(s). Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Received 8 April 2020; revised 19 November 2020; accepted 7 December 2020; published 23 December 2020. I.M. was supported by the Materials Sciences and Engineering Division, Basic Energy Sciences, Office of Science, U. S. Dept. of Energy. F.N. and M.S.R. are grateful to the Villum Foundation and the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 678862) for support. G.R. is grateful for NSF DMR Grant No. 1839271. G.R. is also grateful to the U. S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0019166. NSF and DOE supported G.R.'s time commitment to the project in equal shares.

Attached Files

Published - PhysRevResearch.2.043411.pdf

Submitted - 2003.05648.pdf

Files

2003.05648.pdf
Files (10.3 MB)
Name Size Download all
md5:97d4d3bb2610a96efd10643b0696524e
8.6 MB Preview Download
md5:1dca23f5b057af53e27c27b9d13566e4
1.7 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 20, 2023