Josephson photonics with a two-mode superconducting circuit

We analyze the quantum dynamics of two electromagnetic oscillators coupled in series to a voltage-biased Josephson junction. When the applied voltage leads to a Josephson frequency across the junction which matches the sum of the two mode frequencies, tunneling Cooper pairs excite photons in both mo...

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Main Authors: Armour, Andrew D., Kubala, B., Ankerhold, J.
Format: Article
Published: American Physical Society 2015
Online Access:https://eprints.nottingham.ac.uk/34807/
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author Armour, Andrew D.
Kubala, B.
Ankerhold, J.
author_facet Armour, Andrew D.
Kubala, B.
Ankerhold, J.
author_sort Armour, Andrew D.
building Nottingham Research Data Repository
collection Online Access
description We analyze the quantum dynamics of two electromagnetic oscillators coupled in series to a voltage-biased Josephson junction. When the applied voltage leads to a Josephson frequency across the junction which matches the sum of the two mode frequencies, tunneling Cooper pairs excite photons in both modes simultaneously leading to far-from-equilibrium states. These states display highly nonclassical features including strong antibunching, violation of Cauchy-Schwartz inequalities, and number squeezing. We obtain approximate analytic results for both the regimes of low and high photon occupancies which are supported by a full numerical treatment. The impact of asymmetries between the two modes is explored, revealing a pronounced enhancement of number squeezing when the modes are damped at different rates.
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spelling nottingham-348072020-05-04T17:08:35Z https://eprints.nottingham.ac.uk/34807/ Josephson photonics with a two-mode superconducting circuit Armour, Andrew D. Kubala, B. Ankerhold, J. We analyze the quantum dynamics of two electromagnetic oscillators coupled in series to a voltage-biased Josephson junction. When the applied voltage leads to a Josephson frequency across the junction which matches the sum of the two mode frequencies, tunneling Cooper pairs excite photons in both modes simultaneously leading to far-from-equilibrium states. These states display highly nonclassical features including strong antibunching, violation of Cauchy-Schwartz inequalities, and number squeezing. We obtain approximate analytic results for both the regimes of low and high photon occupancies which are supported by a full numerical treatment. The impact of asymmetries between the two modes is explored, revealing a pronounced enhancement of number squeezing when the modes are damped at different rates. American Physical Society 2015-05-12 Article PeerReviewed Armour, Andrew D., Kubala, B. and Ankerhold, J. (2015) Josephson photonics with a two-mode superconducting circuit. Physical Review B, 91 (184508). pp. 1-12. ISSN 2469-9969 http://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.184508 doi:10.1103/PhysRevB.91.184508 doi:10.1103/PhysRevB.91.184508
spellingShingle Armour, Andrew D.
Kubala, B.
Ankerhold, J.
Josephson photonics with a two-mode superconducting circuit
title Josephson photonics with a two-mode superconducting circuit
title_full Josephson photonics with a two-mode superconducting circuit
title_fullStr Josephson photonics with a two-mode superconducting circuit
title_full_unstemmed Josephson photonics with a two-mode superconducting circuit
title_short Josephson photonics with a two-mode superconducting circuit
title_sort josephson photonics with a two-mode superconducting circuit
url https://eprints.nottingham.ac.uk/34807/
https://eprints.nottingham.ac.uk/34807/
https://eprints.nottingham.ac.uk/34807/