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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

How Much Time Does a Measurement Take?

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Author(s):
Brasil, Carlos Alexandre [1] ; de Castro, L. A. [2] ; Napolitano, R. D. J. [2]
Total Authors: 3
Affiliation:
[1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP - Brazil
[2] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: FOUNDATIONS OF PHYSICS; v. 43, n. 5, p. 642-655, MAY 2013.
Web of Science Citations: 3
Abstract

We consider the problem of measurement using the Lindblad equation, which allows the introduction of time in the interaction between the measured system and the measurement apparatus. We use analytic results, valid for weak system-environment coupling, obtained for a two-level system in contact with a measurer (Markovian interaction) and a thermal bath (non-Markovian interaction), where the measured observable may or may not commute with the system-environment interaction. Analysing the behavior of the coherence, which tends to a value asymptotically close to zero, we obtain an expression for the time of measurement which depends only on the system-measurer coupling, and which does not depend on whether the observable commutes with the system-bath interaction. The behavior of the coherences in the case of strong system-environment coupling, found numerically, indicates that an increase in this coupling decreases the measurement time, thus allowing our expression to be considered the upper limit for the duration of the process. (AU)

FAPESP's process: 09/12460-0 - Quantum error-correction theory during logical operations and finite-duration syndrome measurements
Grantee:Leonardo Andreta de Castro
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 11/19848-4 - Influence of the quantum measurement time on quantum information related phenomena
Grantee:Carlos Alexandre Brasil
Support Opportunities: Scholarships in Brazil - Post-Doctoral