Gravitational Redshift Tests with Atomic Clocks and Atom Interferometers

authored by: Fabio Di Pumpo, Christian Ufrecht, Alexander Friedrich, Enno Giese, Wolfgang P. Schleich, William G. Unruh
Abstract: Atomic interference experiments can probe the gravitational redshift via the internal energy splitting of atoms and thus give direct access to test the universality of the coupling between matter-energy and gravity at different spacetime points. By including possible violations of the equivalence principle in a fully quantized treatment of all atomic degrees of freedom, we characterize how the sensitivity to gravitational redshift violations arises in atomic clocks and atom interferometers, as well as their underlying limitations. Specifically, we show that: (i) Contributions beyond linear order to trapping potentials lead to such a sensitivity of trapped atomic clocks. (ii) Bragg-type interferometers, even with a superposition of internal states, with state-independent, linear interaction potentials are at first insensitive to gravitational redshift tests. However, modified configurations, for example by relaunching the atoms, can mimic such tests under certain conditions and may constitute a competitive alternative. (iii) Guided atom interferometers are comparable to atomic clocks. (iv) Internal transitions lead to state-dependent interaction potentials through which light-pulse atom interferometers can become sensitive to gravitational redshift violations.
Organisation(s): Institute of Quantum Optics
External Organisation(s): Ulm University
Technische Universität Darmstadt
German Aerospace Center (DLR)
Texas A and M University
University of British Columbia
Type: Article
Journal: PRX Quantum
Volume: 2
No. of pages: 23
Publication date: 12.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Physics and Astronomy, General Computer Science, Applied Mathematics, Mathematical Physics, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.48550/arXiv.2104.14391 (Access: Open)
https://doi.org/10.1103/PRXQuantum.2.040333 (Access: Open)

BibTeX

@article{1823b57353b449d682b6cb5b6d8f059c,
title = "Gravitational Redshift Tests with Atomic Clocks and Atom Interferometers",
abstract = "Atomic interference experiments can probe the gravitational redshift via the internal energy splitting of atoms and thus give direct access to test the universality of the coupling between matter-energy and gravity at different spacetime points. By including possible violations of the equivalence principle in a fully quantized treatment of all atomic degrees of freedom, we characterize how the sensitivity to gravitational redshift violations arises in atomic clocks and atom interferometers, as well as their underlying limitations. Specifically, we show that: (i) Contributions beyond linear order to trapping potentials lead to such a sensitivity of trapped atomic clocks. (ii) Bragg-type interferometers, even with a superposition of internal states, with state-independent, linear interaction potentials are at first insensitive to gravitational redshift tests. However, modified configurations, for example by relaunching the atoms, can mimic such tests under certain conditions and may constitute a competitive alternative. (iii) Guided atom interferometers are comparable to atomic clocks. (iv) Internal transitions lead to state-dependent interaction potentials through which light-pulse atom interferometers can become sensitive to gravitational redshift violations.",
author = "{Di Pumpo}, Fabio and Christian Ufrecht and Alexander Friedrich and Enno Giese and Schleich, {Wolfgang P.} and Unruh, {William G.}",
note = "Funding Information: We are grateful to T. Damour for his helpful support regarding the violation model. Moreover, we thank S. Loriani, E. Rasel, A. Roura, D. Schlippert, C. Schubert, and the QUANTUS team for fruitful and interesting discussions. The project “Metrology with interfering Unruh-DeWitt detectors” (MIUnD) is funded by the Carl Zeiss Foun- dation (Carl-Zeiss-Stiftung). The work of IQST is financially supported by the Ministry of Science, Research and Art Baden-W{\"u}rttemberg (Ministerium f{\"u}r Wissenschaft, Forschung und Kunst Baden-W{\"u}rttemberg). The QUAN- TUS and INTENTAS projects are supported by the German Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und Raumfahrt, DLR) with funds provided by the Federal Ministry of Economic Affairs and Energy (Bundesministerium f{\"u}r Wirtschaft und Energie, BMWi) due to an enactment of the German Bundestag under Grants No. 50WM1956 (QUANTUS V) and No. 50WM2177-2178 (INTENTAS). E.G. thanks the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) for a Mercator Fellowship within CRC 1227 (DQ-mat). W.P.S. is grateful to Texas A&M University for a Faculty Fellowship at the Hagler Institute for Advanced Study at Texas A&M University and to Texas A&M AgriLife for the support of this work. W.G.U. acknowledges support by NSERC Canada (Natu- ral Science and Engineering Research Council of Canada), the Hagler Fellowship from HIAS (Hagler Institute for Advanced Study), the Department of Physics and the Insti- tute for Quantum Science and Engineering (IQSE) at Texas A&M University, as well as the Humboldt Foundation. ",
year = "2021",
month = dec,
doi = "10.48550/arXiv.2104.14391",
language = "English",
volume = "2",
journal = "PRX Quantum",
issn = "2691-3399",
publisher = "American Physical Society",
number = "4",
}