Quantum Probes for Ohmic Environments at Thermal Equilibrium

Bibliographic Details
Title: Quantum Probes for Ohmic Environments at Thermal Equilibrium
Authors: Fahimeh Salari Sehdaran, Matteo Bina, Claudia Benedetti, Matteo G. A. Paris
Source: Entropy, Vol 21, Iss 5, p 486 (2019)
Publisher Information: MDPI AG, 2019.
Publication Year: 2019
Collection: LCC:Science
LCC:Astrophysics
LCC:Physics
Subject Terms: open quantum systems, quantum probes, ohmic environments, Science, Astrophysics, QB460-466, Physics, QC1-999
More Details: It is often the case that the environment of a quantum system may be described as a bath of oscillators with an ohmic density of states. In turn, the precise characterization of these classes of environments is a crucial tool to engineer decoherence or to tailor quantum information protocols. Recently, the use of quantum probes in characterizing ohmic environments at zero-temperature has been discussed, showing that a single qubit provides precise estimation of the cutoff frequency. On the other hand, thermal noise often spoil quantum probing schemes, and for this reason we here extend the analysis to a complex system at thermal equilibrium. In particular, we discuss the interplay between thermal fluctuations and time evolution in determining the precision attainable by quantum probes. Our results show that the presence of thermal fluctuations degrades the precision for low values of the cutoff frequency, i.e., values of the order ω c ≲ T (in natural units). For larger values of ω c , decoherence is mostly due to the structure of environment, rather than thermal fluctuations, such that quantum probing by a single qubit is still an effective estimation procedure.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1099-4300
Relation: https://www.mdpi.com/1099-4300/21/5/486; https://doaj.org/toc/1099-4300
DOI: 10.3390/e21050486
Access URL: https://doaj.org/article/01d6a45dfc3c48f4b95edf4f977b3284
Accession Number: edsdoj.01d6a45dfc3c48f4b95edf4f977b3284
Database: Directory of Open Access Journals
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More Details
ISSN:10994300
DOI:10.3390/e21050486
Published in:Entropy
Language:English