Can quantum probes satisfy the weak equivalence principle?
Abstract
We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freelyfalling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP.  Highlights: • Can quantum probes under gravity be approximated as testbodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.
 Authors:
 Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I20133 Milano (Italy)
 (Italy)
 Publication Date:
 OSTI Identifier:
 22617505
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Annals of Physics; Journal Volume: 380; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EQUIVALENCE PRINCIPLE; GRAVITATIONAL FIELDS; QUANTUM MECHANICS; WAVE FUNCTIONS
Citation Formats
Seveso, Luigi, Email: luigi.seveso@unimi.it, Paris, Matteo G.A., and INFN, Sezione di Milano, I20133 Milano. Can quantum probes satisfy the weak equivalence principle?. United States: N. p., 2017.
Web. doi:10.1016/J.AOP.2017.03.021.
Seveso, Luigi, Email: luigi.seveso@unimi.it, Paris, Matteo G.A., & INFN, Sezione di Milano, I20133 Milano. Can quantum probes satisfy the weak equivalence principle?. United States. doi:10.1016/J.AOP.2017.03.021.
Seveso, Luigi, Email: luigi.seveso@unimi.it, Paris, Matteo G.A., and INFN, Sezione di Milano, I20133 Milano. Mon .
"Can quantum probes satisfy the weak equivalence principle?". United States.
doi:10.1016/J.AOP.2017.03.021.
@article{osti_22617505,
title = {Can quantum probes satisfy the weak equivalence principle?},
author = {Seveso, Luigi, Email: luigi.seveso@unimi.it and Paris, Matteo G.A. and INFN, Sezione di Milano, I20133 Milano},
abstractNote = {We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freelyfalling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP.  Highlights: • Can quantum probes under gravity be approximated as testbodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.},
doi = {10.1016/J.AOP.2017.03.021},
journal = {Annals of Physics},
number = ,
volume = 380,
place = {United States},
year = {Mon May 15 00:00:00 EDT 2017},
month = {Mon May 15 00:00:00 EDT 2017}
}

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