University of Oulu

I. Pietikäinen, S. Danilin, K. S. Kumar, A. Vepsäläinen, D. S. Golubev, J. Tuorila, and G. S. Paraoanu Phys. Rev. B 96, 020501,

Observation of the Bloch-Siegert shift in a driven quantum-to-classical transition

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Author: Pietikäinen, I.1; Danilin, S.2; Kumar, K. S.2;
Organizations: 1Nano and Molecular Materials Research Unit, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
2Centre for Quantum Engineering and LTQ, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland
3COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.1 MB)
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Language: English
Published: American Physical Society, 2017
Publish Date: 2018-03-07


We show that the counter-rotating terms of the dispersive qubit-cavity Rabi model can produce relatively large and nonmonotonic Bloch-Siegert shifts in the cavity frequency as the system is driven through a quantum-to-classical transition. Using a weak microwave probe tone, we demonstrate experimentally this effect by monitoring the resonance frequency of a microwave cavity coupled to a transmon and driven by a microwave field with varying power. In the weakly driven regime (quantum phase), the Bloch-Siegert shift appears as a small constant frequency shift, while for a strong drive (classical phase) it presents an oscillatory behavior as a function of the number of photons in the cavity. The experimental results are in agreement with numerical simulations based on the quasienergy spectrum.

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Series: Physical review. B
ISSN: 2469-9950
ISSN-E: 2469-9969
ISSN-L: 2469-9950
Volume: 96
Issue: 2
Article number: 020501
DOI: 10.1103/PhysRevB.96.020501
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
Funding: We are grateful for the financial support from the Academy of Finland (Projects No. 263457 and No. 135135), the Magnus Ehrnrooth Foundation, the Finnish Cultural Foundation, the Vilho, Yrjö, and Kalle Väisälä Foundation, FQXi, Centre of Quantum Engineering at Aalto University (Project QMET), and the Centres of Excellence LTQ (Project No. 250280), and COMP(ProjectsNo. 251748 and No. 284621).
Copyright information: © 2017 American Physical Society. Published in this repository with the kind permission of the publisher.