Entanglement of quantum clocks through gravity
- Author(s)
- Esteban Castro Ruiz, Flaminia Giacomini, Caslav Brukner
- Abstract
In general relativity, the picture of space-time assigns an ideal clock to each world line. Being ideal, gravitational effects due to these clocks are ignored and the flow of time according to one clock is not affected by the presence of clocks along nearby world lines. However, if time is defined operationally, as a pointer position of a physical clock that obeys the principles of general relativity and quantum mechanics, such a picture is, at most, a convenient fiction. Specifically, we show that the general relativistic mass-energy equivalence implies gravitational interaction between the clocks, whereas the quantum mechanical superposition of energy eigenstates leads to a nonfixed metric background. Based only on the assumption that both principles hold in this situation, we show that the clocks necessarily get entangled through time dilation effect, which eventually leads to a loss of coherence of a single clock. Hence, the time as measured by a single clock is not well defined. However, the general relativistic notion of time is recovered in the classical limit of clocks.
- Organisation(s)
- Quantum Optics, Quantum Nanophysics and Quantum Information
- External organisation(s)
- Österreichische Akademie der Wissenschaften (ÖAW)
- Journal
- Proceedings of the National Academy of Sciences of the United States of America (PNAS)
- Volume
- 114
- Pages
- E2303-E2309
- No. of pages
- 7
- ISSN
- 0027-8424
- DOI
- https://doi.org/10.1073/pnas.1616427114
- Publication date
- 03-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103025 Quantum mechanics, 103028 Theory of relativity
- Keywords
- ASJC Scopus subject areas
- General
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/entanglement-of-quantum-clocks-through-gravity(a193ec87-8651-4eae-b3ef-5c2ef69d1a21).html