Particle production in ultrastrong-coupling waveguide QED

Nicolas Gheeraert, Xin H. H. Zhang, Théo Sépulcre, Soumya Bera, Nicolas Roch, Harold U. Baranger, and Serge Florens
Phys. Rev. A 98, 043816 – Published 8 October 2018

Abstract

Understanding large-scale interacting quantum matter requires dealing with the huge number of quanta that are produced by scattering even a few particles against a complex quantum object. Prominent examples are found from high-energy cosmic ray showers, to the optical or electrical driving of degenerate Fermi gases. We tackle this challenge in the context of many-body quantum optics, as motivated by the recent developments of circuit quantum electrodynamics at ultrastrong coupling. The issue of particle production is addressed quantitatively with a simple yet powerful concept rooted in the quantum superposition principle of multimode coherent states. This key idea is illustrated by the study of multiphoton emission from a single two-level artificial atom coupled to a high impedance waveguide, driven by a nearly monochromatic coherent tone. We find surprisingly that the off-resonant inelastic emission line shape is dominated by broadband particle production, due to the large phase space associated with contributions that do not conserve the number of excitations. Such frequency conversion processes produce striking signatures in time correlation measurements, which can be tested experimentally in quantum waveguides. These ideas open new directions for the simulation of a variety of physical systems, from polaron dynamics in solids to complex superconducting quantum architectures.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
5 More
  • Received 12 February 2018

DOI:https://doi.org/10.1103/PhysRevA.98.043816

©2018 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Nicolas Gheeraert1, Xin H. H. Zhang2, Théo Sépulcre1, Soumya Bera3, Nicolas Roch1, Harold U. Baranger2, and Serge Florens1

  • 1Institut Néel, CNRS and Université Grenoble Alpes, F-38042 Grenoble, France
  • 2Department of Physics, Duke University, P.O. Box 90305, Durham, North Carolina 27708, USA
  • 3Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 98, Iss. 4 — October 2018

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review A

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×