• Featured in Physics
  • Editors' Suggestion

Measurement of the Decay of Fock States in a Superconducting Quantum Circuit

H. Wang, M. Hofheinz, M. Ansmann, R. C. Bialczak, E. Lucero, M. Neeley, A. D. O’Connell, D. Sank, J. Wenner, A. N. Cleland, and John M. Martinis
Phys. Rev. Lett. 101, 240401 – Published 8 December 2008
Physics logo See Viewpoint: Filling a cavity with photons, and watching them leave


We demonstrate the controlled generation of Fock states with up to 15 photons in a microwave coplanar waveguide resonator coupled to a superconducting phase qubit. The subsequent decay of the Fock states, due to dissipation, is then monitored by varying the time delay between preparing the state and performing a number-state analysis. We find that the decay dynamics can be described by a master equation where the lifetime of the n-photon Fock state scales as 1/n, in agreement with theory. We have also generated a coherent state in the microwave resonator, and monitored its decay process. We demonstrate that the coherent state maintains a Poisson distribution as it decays, with an average photon number that decreases with the same characteristic decay time as the one-photon Fock state.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 21 August 2008


©2008 American Physical Society


Key Image

Filling a cavity with photons, and watching them leave

Published 8 December 2008

Preparing a harmonic oscillator in a state with a well-defined energy is a tricky business. With the new tools provided by cavity and circuit quantum electrodynamics it is now possible to make these pure quantum states and watch how they evolve in time.

See more in Physics

Authors & Affiliations

H. Wang, M. Hofheinz, M. Ansmann, R. C. Bialczak, E. Lucero, M. Neeley, A. D. O’Connell, D. Sank, J. Wenner, A. N. Cleland*, and John M. Martinis

  • Department of Physics, University of California, Santa Barbara, California 93106, USA

  • *anc@physics.ucsb.edu
  • martinis@physics.ucsb.edu

See Also

Process Tomography of Field Damping and Measurement of Fock State Lifetimes by Quantum Nondemolition Photon Counting in a Cavity

M. Brune, J. Bernu, C. Guerlin, S. Deléglise, C. Sayrin, S. Gleyzes, S. Kuhr, I. Dotsenko, J. M. Raimond, and S. Haroche
Phys. Rev. Lett. 101, 240402 (2008)

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Vol. 101, Iss. 24 — 12 December 2008

Reuse & Permissions
Access Options
Heating up of Superconductors
January 27, 2017

This collection marks the 30th anniversary of the discovery of high-temperature superconductors. The papers selected highlight some of the advances that have been made to date, both in understanding why these compounds behave in the way they do, and in utilizing them in applications. The papers included in the collection have been made free to read.

APS and CERN Sign Open Access Agreement for SCOAP3

APS and CERN, the host organization of SCOAP3 (Sponsoring Consortium for Open Access Publishing in Particle Physics), have signed an agreement to make the high-energy physics (HEP) articles published in three leading APS journals open access beginning January 1, 2018. This agreement acts to support the publishing of open access content for wider benefit of the HEP community.

Authorization Required




Sign up to receive regular email alerts from Physical Review Letters

Log In



Article Lookup

Paste a citation or DOI

Enter a citation