Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Contemporary Physics

Interaction of mesoscopic Josephson devices with non-classical microwaves

Apostol Vourdas

Published May 1, 2003• 5 citations
Publisher

Abstract

Mesoscopic Josephson devices, interacting with non-classical microwaves, are studied. The phase difference in Josephson's equations is a quantum mechanical operator, whose expectation value with respect to the density matrix describing the microwaves, determines the current. Dual phenomena with vortex condensates in Josephson array insulators are also considered. Dual Josephson junctions for vortices, made from two insulators separated by a weak link through which the vortices tunnel, are described by dual Josephson equations.

DOI
10.1080/0010751031000095116

Related papers

Mesoscopic Josephson arrays interactingwith non-classical electromagnetic fields and theirapplications

A. Konstadopoulou, J.M. Hollingworth, M. J. Everitt +3 more

A ring made from a Josephson array in the insulating phase is considered. The ring contains a ‘dual Josephson junction’ (Josephson junction for vortices). External non-classical electromagnetic fields are coupled to the device and interact with the vortices that circulate the ring. The time evolution of this two-mode fully quantum mechanical system is studied. The effect of the quantum statistics of the photons on the quantum statistics of the vortices is discussed. The entanglement between the two systems is quantified.

IEE Proceedings - Science Measurement and Technology•Sep 5, 2001•3 citations

Tunneling of vortices through a weak link in an insulating Josephson array

Apostol Vourdas, Timothy P. Spiller, Terrence D. Clark +1 more

A Josephson array ring in the insulating phase with circulating vortices is considered. The persistent vortex current is calculated as a function of the charge at the center of the ring and the temperature, for the case of negligible dissipation. A weak link is introduced in the ring and the tunneling of vortices through it is described with the ``dual Josephson equations.'' The Hamiltonian that describes the interaction of these devices with electromagnetic fields is quantized. The use of such nonlinear devices as amplifiers and frequency converters of nonclassical microwaves is discussed.

Physical review. B, Condensed matter•Feb 5, 2001•3 citations

Entangled quantum currents in distant mesoscopic Josephson junctions

Dimitris I. Tsomokos, Chong, C.C., Apostol Vourdas

Two mesoscopic SQUID rings which are far from each other, are considered.A source of twomode nonclassical microwaves irradiates the two rings with correlated photons.The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves, yield the experimentally observed currents.Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified.Results for two different examples that involve microwaves in number states and coherent states are derived.It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings, are correlated.

•Jan 1, 2004•5 citations

Entangled quantum currents in distant mesoscopic Josephson junctions

Dimitris I. Tsomokos, C C Chong, Apostol Vourdas

Two mesoscopic SQUID rings which are far from each other, are considered. A source of two-mode nonclassical microwaves irradiates the two rings with correlated photons. The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves, yield the experimentally observed currents. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. Results for two different examples that involve microwaves in number states and coherent states are derived. It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings, are correlated.

arXiv:cond-mat/0411439•Journal of Physics Condensed Matter•Dec 7, 2004•6 citations

Linear response theory of Josephson junction arrays in a microwave cavity

Samuel A. Wilkinson, Jared H. Cole

Recent experiments on Josephson junction arrays (JJAs) in microwave cavities have opened up a new avenue for investigating the properties of these devices while minimizing the amount of external noise coming from the measurement apparatus itself. These experiments have already shown promise for probing many-body quantum effects in JJAs. In this work, we develop a general theoretical description of such experiments by deriving a quantum phase model for planar JJAs containing quantized vortices. The dynamical susceptibility of this model is calculated for some simple circuits, and signatures of the injection of additional vortices are identified. The effects of decoherence are considered via a Lindblad master equation.

arXiv:1811.01737•Physical review. B./Physical review. B•Apr 2, 2019•2 citations

Dynamics of Josephson junction arrays—Microscopic investigations and applications

Thomas Doderer

We discuss the dynamics of two-dimensional arrays of Josephson junctions in the overdamped regime. Our discussion is restricted to “classical” arrays, where the Josephson coupling energy is much larger than the charging energy. Such arrays represent a highly controllable system to study the dynamics of vortices. Furthermore, they are promising for applications like, e.g., a coherent microwave source. The experiments have been performed with arrays of Nb/AlOx/Nb-tunnel junctions allowing a high degree of junction uniformity across the array. The typical array size is 10×10 junctions. We show spatially resolved measurement results obtained by low-temperature scanning electron microscopy, and demonstrate the merit of these investigations for the clarification of complex regimes of vortex dynamics as well as for the optimization of coherent microwave sources. In the case of external microwave irradiation with increasing power, a continuous transition from a non-locked to a completely locked oscillation state is presented. In addition, we report on the quantitative measurement of the emitted microwave power from the arrays.

AIP conference proceedings•Jan 1, 1998•0 citations
Mesoscopic Josephson devices, interacting with non-classical microwaves, are studied. The phase difference in Josephson's equations is a quantum mechanical operator, whose expectation value with respect to the density matrix describing the microwaves, determines the current. Dual phenomena with vortex condensates in Josephson array insulators are also considered. Dual Josephson junctions for vortices, made from two insulators separated by a weak link through which the vortices tunnel, are described by dual Josephson equations.
A ring made from a Josephson array in the insulating phase is considered. The ring contains a ‘dual Josephson junction’ (Josephson junction for vortices). External non-classical electromagnetic fields are coupled to the device and interact with the vortices that circulate the ring. The time evolution of this two-mode fully quantum mechanical system is studied. The effect of the quantum statistics of the photons on the quantum statistics of the vortices is discussed. The entanglement between the two systems is quantified.
A Josephson array ring in the insulating phase with circulating vortices is considered. The persistent vortex current is calculated as a function of the charge at the center of the ring and the temperature, for the case of negligible dissipation. A weak link is introduced in the ring and the tunneling of vortices through it is described with the ``dual Josephson equations.'' The Hamiltonian that describes the interaction of these devices with electromagnetic fields is quantized. The use of such nonlinear devices as amplifiers and frequency converters of nonclassical microwaves is discussed.
Two mesoscopic SQUID rings which are far from each other, are considered.A source of twomode nonclassical microwaves irradiates the two rings with correlated photons.The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves, yield the experimentally observed currents.Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified.Results for two different examples that involve microwaves in number states and coherent states are derived.It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings, are correlated.
Two mesoscopic SQUID rings which are far from each other, are considered. A source of two-mode nonclassical microwaves irradiates the two rings with correlated photons. The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves, yield the experimentally observed currents. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. Results for two different examples that involve microwaves in number states and coherent states are derived. It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings, are correlated.
Recent experiments on Josephson junction arrays (JJAs) in microwave cavities have opened up a new avenue for investigating the properties of these devices while minimizing the amount of external noise coming from the measurement apparatus itself. These experiments have already shown promise for probing many-body quantum effects in JJAs. In this work, we develop a general theoretical description of such experiments by deriving a quantum phase model for planar JJAs containing quantized vortices. The dynamical susceptibility of this model is calculated for some simple circuits, and signatures of the injection of additional vortices are identified. The effects of decoherence are considered via a Lindblad master equation.
We discuss the dynamics of two-dimensional arrays of Josephson junctions in the overdamped regime. Our discussion is restricted to “classical” arrays, where the Josephson coupling energy is much larger than the charging energy. Such arrays represent a highly controllable system to study the dynamics of vortices. Furthermore, they are promising for applications like, e.g., a coherent microwave source. The experiments have been performed with arrays of Nb/AlOx/Nb-tunnel junctions allowing a high degree of junction uniformity across the array. The typical array size is 10×10 junctions. We show spatially resolved measurement results obtained by low-temperature scanning electron microscopy, and demonstrate the merit of these investigations for the clarification of complex regimes of vortex dynamics as well as for the optimization of coherent microwave sources. In the case of external microwave irradiation with increasing power, a continuous transition from a non-locked to a completely locked oscillation state is presented. In addition, we report on the quantitative measurement of the emitted microwave power from the arrays.