Reflective Amplification without Population Inversion from a Strongly Driven Superconducting Qubit

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

35 Scopus Citations
View graph of relations

Author(s)

  • P. Y. Wen
  • A. F. Kockum
  • H. Ian
  • J. C. Chen
  • F. Nori

Detail(s)

Original languageEnglish
Article number063603
Journal / PublicationPhysical Review Letters
Volume120
Issue number6
Publication statusPublished - 6 Feb 2018
Externally publishedYes

Abstract

Amplification of optical or microwave fields is often achieved by strongly driving a medium to induce population inversion such that a weak probe can be amplified through stimulated emission. Here we strongly couple a superconducting qubit, an artificial atom, to the field in a semi-infinite waveguide. When driving the qubit strongly on resonance such that a Mollow triplet appears, we observe a 7% amplitude gain for a weak probe at frequencies in between the triplet. This amplification is not due to population inversion, neither in the bare qubit basis nor in the dressed-state basis, but instead results from a four-photon process that converts energy from the strong drive to the weak probe. We find excellent agreement between the experimental results and numerical simulations without any free fitting parameters. Since our device consists of a single two-level artificial atom, the simplest possible quantum system, it can be viewed as the most fundamental version of a four-wave-mixing parametric amplifier.

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to lbscholars@cityu.edu.hk.

Citation Format(s)

Reflective Amplification without Population Inversion from a Strongly Driven Superconducting Qubit. / Wen, P. Y.; Kockum, A. F.; Ian, H. et al.
In: Physical Review Letters, Vol. 120, No. 6, 063603, 06.02.2018.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review