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

Circuital Representation of Quantum Devices in Entangled States

G. Slepyan, A. Boag, V. Mordachev, E. Sinkevich, S. Maksimenko, P. Kuzhir, M. E. Portnoi, G. Miano, Antonio Maffucci

Published Jan 1, 2015• 0 citations
OpenAlex

Abstract

In this paper we introduce the concept of equivalent admittance to model a “quantum load” with entanglement in the framework of the circuit theory. The load is given by a pair of quantum dots, each of them interacting with two nano-electrodes, e.g. nanowires. We define and evaluate an equivalent admittance describing a quantum device made by a pair of two-level objects, coupled via entangled states.

Related papers

Equivalent electrical multiport for quantum systems in entangled states

Gregory Ya. Slepyan, Amir Boag, Vladimir I. Mordachev +6 more

This paper introduces the concept of equivalent electrical multiport for a quantum device made of a pair of two-level objects, coupled via entanglement. The coupled pair is described in terms of an equivalent 2×2 admittance matrix, derived from the theory of the generalized susceptibility. This result provides a valuable tool to analyze quantum circuits in the frame of the classical circuit theory. The study of the properties of the admittance matrix highlights the effect of a new coupling mechanism, due to entanglement, which adds to the classical electromagnetic coupling.

IEEE International Conference on Nanotechnology (IEEE-NANO)•Jul 1, 2015•2 citations

On small signal equivalent circuit models for quantum dots

Giovanni Miano, Carlo Forestiere, Amir Boag +2 more

Summary In this paper, we introduce small signal equivalent circuit models for quantum dots at equilibrium driven by classical electromagnetic fields. We investigate both an isolated quantum dot and a pair of interacting quantum dots coupled by the electric dipole–dipole interaction. In particular, we derive the impulse responses of the equivalent circuit elements from the density operator of the quantum dots. The use of equivalent circuit elements for complex systems of quantum dots may greatly simplify the analysis and the design of light‐matter interaction processes at the nanoscale. Copyright © 2017 John Wiley & Sons, Ltd.

International Journal of Circuit Theory and Applications•Mar 22, 2017•4 citations

Theory of semiconductor quantum-wire-based single- and two-qubit gates

Tobias Zibold, Peter Vogl, Andrea Bertoni

A $\mathrm{Ga}\mathrm{As}∕\mathrm{Al}\mathrm{Ga}\mathrm{As}$ based two-qubit quantum device that allows the controlled generation and straightforward detection of entanglement by measuring a stationary current-voltage characteristics is proposed. We have developed a two-particle Green's function method of open systems and calculate the properties of three-dimensional interacting entangled systems nonperturbatively. We present concrete device designs and detailed charge-self-consistent predictions. One of the qubits is an all-electric Mach-Zehnder interferometer that consists of two electrostatically defined quantum wires with coupling windows, whereas the second qubit is an electrostatically defined double quantum dot located in a second two-dimensional electron gas beneath the quantum wires. We find that the entanglement of the device can be controlled externally by tuning the tunneling coupling between the two quantum dots.

arXiv:0710.3572•Physical Review B•Nov 1, 2007•21 citations

Spin qubits in double quantum dots: Entanglement versus the Kondo effect

A. Ramšak, Jernej Mravlje, Rok Žitko +1 more

We investigate the competition between pair entanglement of two spin qubits in double quantum dots attached to leads with various topologies and the separate entanglement of each spin with nearby electrodes. Universal behavior of entanglement is demonstrated in dependence on the mutual interactions between the spin qubits, the coupling to their environment, temperature, and magnetic field. As a consequence of quantum phase transition an abrupt switch between fully entangled and unentangled states takes place when the dots are coupled in parallel.

arXiv:quant-ph/0608065•Physical Review B•Dec 21, 2006•33 citations

Structure of resistive networks for dispersive tunnel processes

G. Brunk, Ch. Zurbrügg, H. Lübbig

Fundamental construction principles for equivalent circuits for superconducting pair and quasiparticle tunnel junctions are discussed. To the lowest order of microscopic tunneling, the two basic features of the corresponding macroscopic dynamics, i.e the energy-neutral nonlinear self-coupling of the quantum phase shift and the energy-effective tunnel admittance, are discussed in the framework of linear response theory (equivalent to the KUBO formalism) and are represented by means of the corresponding equivalent two-subcircuit network. Approximation formulas describing a singularity-equivalent model are discussed in detail, and consequences for secondary quantum processes are indicated.>

IEEE Transactions on Magnetics•Mar 1, 1989•2 citations

Equivalent circuits for two‐state quantum systems

Pier Paolo Civalleri, Marco Gilli, Michele Bonnin

Abstract The development of nanocircuits designed to ultimately interact with classical electromagnetic environments demands a description of their performance in circuit terms, i.e. in terms of voltages and currents for incident, reflected and transmitted waves. A class of quantum systems which are particularly promising for applications (e.g. in spintronics) and at the same time easy to analyse and to understand physically are the two‐state systems. Here, we present equivalent circuits for a generic two‐state quantum system imbedded in a one‐port or two‐port structure guiding a linearly polarized electromagnetic wave. For the sake of concreteness we explicitly refer to a system of spin ½ particles whose magnetic moments are aligned with the axis of the guiding structure by a strong constant magnetic field; but the formalism can be easily extended to particles endowed with electric dipole moments or any other system with two degrees of freedom. Copyright © 2007 John Wiley & Sons, Ltd.

International Journal of Circuit Theory and Applications•Apr 12, 2007•9 citations
In this paper we introduce the concept of equivalent admittance to model a “quantum load” with entanglement in the framework of the circuit theory. The load is given by a pair of quantum dots, each of them interacting with two nano-electrodes, e.g. nanowires. We define and evaluate an equivalent admittance describing a quantum device made by a pair of two-level objects, coupled via entangled states.
This paper introduces the concept of equivalent electrical multiport for a quantum device made of a pair of two-level objects, coupled via entanglement. The coupled pair is described in terms of an equivalent 2×2 admittance matrix, derived from the theory of the generalized susceptibility. This result provides a valuable tool to analyze quantum circuits in the frame of the classical circuit theory. The study of the properties of the admittance matrix highlights the effect of a new coupling mechanism, due to entanglement, which adds to the classical electromagnetic coupling.
Summary In this paper, we introduce small signal equivalent circuit models for quantum dots at equilibrium driven by classical electromagnetic fields. We investigate both an isolated quantum dot and a pair of interacting quantum dots coupled by the electric dipole–dipole interaction. In particular, we derive the impulse responses of the equivalent circuit elements from the density operator of the quantum dots. The use of equivalent circuit elements for complex systems of quantum dots may greatly simplify the analysis and the design of light‐matter interaction processes at the nanoscale. Copyright © 2017 John Wiley & Sons, Ltd.
A GaAs∕AlGaAs\mathrm{Ga}\mathrm{As}∕\mathrm{Al}\mathrm{Ga}\mathrm{As}GaAs∕AlGaAs based two-qubit quantum device that allows the controlled generation and straightforward detection of entanglement by measuring a stationary current-voltage characteristics is proposed. We have developed a two-particle Green's function method of open systems and calculate the properties of three-dimensional interacting entangled systems nonperturbatively. We present concrete device designs and detailed charge-self-consistent predictions. One of the qubits is an all-electric Mach-Zehnder interferometer that consists of two electrostatically defined quantum wires with coupling windows, whereas the second qubit is an electrostatically defined double quantum dot located in a second two-dimensional electron gas beneath the quantum wires. We find that the entanglement of the device can be controlled externally by tuning the tunneling coupling between the two quantum dots.
We investigate the competition between pair entanglement of two spin qubits in double quantum dots attached to leads with various topologies and the separate entanglement of each spin with nearby electrodes. Universal behavior of entanglement is demonstrated in dependence on the mutual interactions between the spin qubits, the coupling to their environment, temperature, and magnetic field. As a consequence of quantum phase transition an abrupt switch between fully entangled and unentangled states takes place when the dots are coupled in parallel.
Fundamental construction principles for equivalent circuits for superconducting pair and quasiparticle tunnel junctions are discussed. To the lowest order of microscopic tunneling, the two basic features of the corresponding macroscopic dynamics, i.e the energy-neutral nonlinear self-coupling of the quantum phase shift and the energy-effective tunnel admittance, are discussed in the framework of linear response theory (equivalent to the KUBO formalism) and are represented by means of the corresponding equivalent two-subcircuit network. Approximation formulas describing a singularity-equivalent model are discussed in detail, and consequences for secondary quantum processes are indicated.>
Abstract The development of nanocircuits designed to ultimately interact with classical electromagnetic environments demands a description of their performance in circuit terms, i.e. in terms of voltages and currents for incident, reflected and transmitted waves. A class of quantum systems which are particularly promising for applications (e.g. in spintronics) and at the same time easy to analyse and to understand physically are the two‐state systems. Here, we present equivalent circuits for a generic two‐state quantum system imbedded in a one‐port or two‐port structure guiding a linearly polarized electromagnetic wave. For the sake of concreteness we explicitly refer to a system of spin ½ particles whose magnetic moments are aligned with the axis of the guiding structure by a strong constant magnetic field; but the formalism can be easily extended to particles endowed with electric dipole moments or any other system with two degrees of freedom. Copyright © 2007 John Wiley & Sons, Ltd.