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Title: Reversible and irreversible dynamics of a qubit interacting with a small environment

Abstract

We analyze the dynamics of a system qubit interacting by means of a sequence of pairwise collisions with an environment consisting of just two qubits. We show that the density operator of the qubits approaches a common time-averaged equilibrium state, characterized by large fluctuations, only for a random sequence of collisions. For a regular sequence of collisions the qubit states of the system and of the reservoir undergo instantaneous periodic oscillations and do not relax to a common state. Furthermore we show that pure bipartite entanglement is developed only when at least two qubits are initially in the same pure state while otherwise also genuine multipartite entanglement builds up.

Authors:
 [1];  [2];  [3]
  1. CNISM, CNR-INFM and Center for Nonlinear and Complex Systems, Universita degli Studi dell'Insubria, via Valleggio 11, I-22100 Como (Italy)
  2. (Italy)
  3. NEST--CNR (INFM) and Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, via Archirafi 36, I-90123 Palermo (Italy)
Publication Date:
OSTI Identifier:
20982462
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.75.052110; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLLISIONS; EQUILIBRIUM; OSCILLATIONS; PERIODICITY; QUANTUM COMPUTERS; QUANTUM ENTANGLEMENT; QUANTUM MECHANICS; QUBITS; RANDOMNESS

Citation Formats

Benenti, Giuliano, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, I-20133 Milano, and Palma, G. Massimo. Reversible and irreversible dynamics of a qubit interacting with a small environment. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.052110.
Benenti, Giuliano, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, I-20133 Milano, & Palma, G. Massimo. Reversible and irreversible dynamics of a qubit interacting with a small environment. United States. doi:10.1103/PHYSREVA.75.052110.
Benenti, Giuliano, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, I-20133 Milano, and Palma, G. Massimo. Tue . "Reversible and irreversible dynamics of a qubit interacting with a small environment". United States. doi:10.1103/PHYSREVA.75.052110.
@article{osti_20982462,
title = {Reversible and irreversible dynamics of a qubit interacting with a small environment},
author = {Benenti, Giuliano and Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, I-20133 Milano and Palma, G. Massimo},
abstractNote = {We analyze the dynamics of a system qubit interacting by means of a sequence of pairwise collisions with an environment consisting of just two qubits. We show that the density operator of the qubits approaches a common time-averaged equilibrium state, characterized by large fluctuations, only for a random sequence of collisions. For a regular sequence of collisions the qubit states of the system and of the reservoir undergo instantaneous periodic oscillations and do not relax to a common state. Furthermore we show that pure bipartite entanglement is developed only when at least two qubits are initially in the same pure state while otherwise also genuine multipartite entanglement builds up.},
doi = {10.1103/PHYSREVA.75.052110},
journal = {Physical Review. A},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}