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

Chinese Physics Letters

Multiple System-Decomposition Method for Avoiding Quantum Decoherence

J. Jeknić-Dugić, M. Dugić

Published Feb 1, 2008• 6 citations
Publisher

Abstract

Decomposition of a composite system C into different subsystems, A + B or D + E, may help in avoiding decoherence. For example, the environment-induced decoherence for an A+B system need not destroy entanglement present in the D + E system (A + B = C = D + E). This new approach opens some questions also in the foundations of the quantum computation theory that might eventually lead to a new model of quantum computation.

DOI
10.1088/0256-307x/25/2/006

Related papers

Decomposition of a Finite Quantum System into Subsystems: Symbolic–Numerical Approach

Vladimir V. Kornyak

Abstract Any Hilbert space with composite dimension can be represented as a tensor product of Hilbert spaces of lower dimensions. This factorization makes it possible to decompose a quantum system into subsystems. We propose a model based on finite quantum mechanics for the constructive study of decompositions of an isolated quantum system into subsystems. To study the behavior of the composite systems resulting from the decompositions, we develop algorithms based on methods of computer algebra and computational group theory.

Programming and Computer Software•Jul 17, 2022•2 citations

Lower bounds for decoherence

Lawrence S. Schulman

Both quantum computing and tests of certain theories of quantum measurement require tight control over entanglement of the degrees of freedom of the system with those of the environment. In particular, one wishes to avoid entanglement-induced decoherence due to the confining of the system by the macroscopic apparatus. Nonetheless, when the system interacts with its walls (treated quantum mechanically), there is an inevitable intertwining of degrees of freedom. We show that this need not lead to entanglement, hence decoherence. It will generally lead to error. The wave function optimization required to avoid decoherence is also examined.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jul 1, 1997•0 citations

DECOHERENCE IN COMPOSITE QUANTUM OPEN SYSTEMS: THE EFFECTIVENESS OF UNSTABLE DEGREES OF FREEDOM

FERNANDO C. LOMBARDO, PAULA I. VILLAR

The effect induced by an environment on a composite quantum system is studied. The model considers the composite system as comprised by a subsystem A coupled to a subsystem B which is also coupled to an external environment. We studied all possible four combinations of subsystems A and B made up with a harmonic oscillator and an upside down oscillator. We analyzed the decoherence suffered by subsystem A due to an effective environment composed by subsystem B and the external reservoir. In all the cases we found that subsystem A decoheres even though it interacts with the environment only through its sole coupling to B. However, the effectiveness of the diffusion depends on the unstable nature of subsystem A and B. Therefore, the role of this degree of freedom in the effective environment is analyzed in detail.

arXiv:quant-ph/0507107•International Journal of Modern Physics B•Aug 10, 2006•1 citation

Decoherence in composite quantum open systems: The effectiveness of unstable degrees of freedom

Fernando C. Lombardo, Paula I. Villar

The effect induced by an environment on a composite quantum system is studied. The model considers the composite system as comprised by a subsystem A coupled to a subsystem B which is also coupled to an external environment. We studied all possible four combinations of subsystems A and B made up with a harmonic oscillator and an upside down oscillator. We analyzed the decoherence suffered by subsystem A due to an effective environment composed by subsystem B and the external reservoir. In all the cases we found that subsystem A decoheres even though it interacts with the environment only through its sole coupling to B. However, the effectiveness of the diffusion depends on the unstable nature of subsystem A and B. Therefore, the role of this degree of freedom in the effective environment is analyzed in detail. © World Scientific Publishing Company.

•Dec 1, 2006•1 citation

Decomposition of non-composite quantum systems

Додин Дмитрий Валерьевич, I. G. Kovalenko, Alexander I. Lvovsky

A composite quantum system is a fundamental object in quantum informatics. A composite quantum system is considered a system whose dimension is a composite integer number whereas the prime integers may only correspond to non‐composite systems. Entanglement and the procedure of reduction to a subsystem via averaging over environment are only formulated for composite systems. In the present report we introduce a procedure of decomposition into ‘subsystems’ for a system whose dimension is an arbitrary number including a prime integer. This procedure generalizes the standard procedure of reduction. In the particular case of a non‐composite system the space of states of the decomposed system splits into direct sum of subspaces of states and the average dimension of subspaces is a fractional number. We compare the properties of the introduced procedure of decomposition and the standard separation into subsystems.

AIP conference proceedings•Jan 1, 2009•0 citations

Immunizing quantum information against decoherence via decoherence-free environments

Murat Çetinbaş, Gary W. Leach

We construct decoherence-free environments (DFEs) within the Hamiltonian formalism and derive an exact equation of motion for a quantum subsystem interacting with a DFE. We discuss the feasibility of DFEs as a means to protect the quantum information in subsystem degrees of freedom. By studying a number of examples we show how to avoid entanglement-induced decoherence as well as decoherence induced by incoherence dynamics in a quantum subsystem coupled to a DFE.

Journal of Physics A Mathematical and Theoretical•Feb 24, 2011•4 citations
Decomposition of a composite system C into different subsystems, A + B or D + E, may help in avoiding decoherence. For example, the environment-induced decoherence for an A+B system need not destroy entanglement present in the D + E system (A + B = C = D + E). This new approach opens some questions also in the foundations of the quantum computation theory that might eventually lead to a new model of quantum computation.
Abstract Any Hilbert space with composite dimension can be represented as a tensor product of Hilbert spaces of lower dimensions. This factorization makes it possible to decompose a quantum system into subsystems. We propose a model based on finite quantum mechanics for the constructive study of decompositions of an isolated quantum system into subsystems. To study the behavior of the composite systems resulting from the decompositions, we develop algorithms based on methods of computer algebra and computational group theory.
Both quantum computing and tests of certain theories of quantum measurement require tight control over entanglement of the degrees of freedom of the system with those of the environment. In particular, one wishes to avoid entanglement-induced decoherence due to the confining of the system by the macroscopic apparatus. Nonetheless, when the system interacts with its walls (treated quantum mechanically), there is an inevitable intertwining of degrees of freedom. We show that this need not lead to entanglement, hence decoherence. It will generally lead to error. The wave function optimization required to avoid decoherence is also examined.
The effect induced by an environment on a composite quantum system is studied. The model considers the composite system as comprised by a subsystem A coupled to a subsystem B which is also coupled to an external environment. We studied all possible four combinations of subsystems A and B made up with a harmonic oscillator and an upside down oscillator. We analyzed the decoherence suffered by subsystem A due to an effective environment composed by subsystem B and the external reservoir. In all the cases we found that subsystem A decoheres even though it interacts with the environment only through its sole coupling to B. However, the effectiveness of the diffusion depends on the unstable nature of subsystem A and B. Therefore, the role of this degree of freedom in the effective environment is analyzed in detail.
The effect induced by an environment on a composite quantum system is studied. The model considers the composite system as comprised by a subsystem A coupled to a subsystem B which is also coupled to an external environment. We studied all possible four combinations of subsystems A and B made up with a harmonic oscillator and an upside down oscillator. We analyzed the decoherence suffered by subsystem A due to an effective environment composed by subsystem B and the external reservoir. In all the cases we found that subsystem A decoheres even though it interacts with the environment only through its sole coupling to B. However, the effectiveness of the diffusion depends on the unstable nature of subsystem A and B. Therefore, the role of this degree of freedom in the effective environment is analyzed in detail. © World Scientific Publishing Company.
A composite quantum system is a fundamental object in quantum informatics. A composite quantum system is considered a system whose dimension is a composite integer number whereas the prime integers may only correspond to non‐composite systems. Entanglement and the procedure of reduction to a subsystem via averaging over environment are only formulated for composite systems. In the present report we introduce a procedure of decomposition into ‘subsystems’ for a system whose dimension is an arbitrary number including a prime integer. This procedure generalizes the standard procedure of reduction. In the particular case of a non‐composite system the space of states of the decomposed system splits into direct sum of subspaces of states and the average dimension of subspaces is a fractional number. We compare the properties of the introduced procedure of decomposition and the standard separation into subsystems.