An experiment to test the discreteness of time

Marios Christodoulou; Andrea Di Biagio; Pierre Martin-Dussaud

doi:10.22331/q-2022-10-06-826

An experiment to test the discreteness of time

Marios Christodoulou^1,2, Andrea Di Biagio^1,3,4, and Pierre Martin-Dussaud^4,5,6

¹Institute for Quantum Optics and Quantum Information (IQOQI) Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
²Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
³Dipartimento di Fisica, La Sapienza Università di Roma, Piazzale Aldo Moro 5, Roma, Italy
⁴Aix-Marseille Univ, Université de Toulon, CNRS, CPT, Marseille, France
⁵Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
⁶Basic Research Community for Physics e.V., Mariannenstraße 89, Leipzig, Germany

Published:	2022-10-06, volume 6, page 826
Eprint:	arXiv:2007.08431v7
Doi:	https://doi.org/10.22331/q-2022-10-06-826
Citation:	Quantum 6, 826 (2022).

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Abstract

Time at the Planck scale ($\sim 10^{-44} \mathrm{s}$) is an unexplored physical regime. It is widely believed that probing Planck time will remain for long an impossible task. Yet, we propose an experiment to test the discreteness of time at the Planck scale and estimate that it is not far removed from current technological capabilities.

Featured image: Spacetime view of the proposed experiment. A small mass $m$ undergoes a spin-dependent path superposition in the gravitational field of another mass $M$. The two branches accumulate a difference in phase $\delta\phi$ due to the gravitational interaction. In general relativistic terms, the difference in phase is due to a difference $\delta\tau$ in proper times along the two trajectories: $\delta\phi=\frac{m}{m_P}\frac{\delta\tau}{t_P},$ where $m_P$ and $t_P$ are the Planck mass and Planck time, respectively. If $\delta\tau$ can only take a finite set of values, then so does $\delta\phi$. We show that, under some assumptions, there exists a range of experimental parameters that allow to detect a hypothetical granularity of time.

► BibTeX data

@article{Christodoulou2022experimenttotest,
  doi = {10.22331/q-2022-10-06-826},
  url = {https://doi.org/10.22331/q-2022-10-06-826},
  title = {An experiment to test the discreteness of time},
  author = {Christodoulou, Marios and Biagio, Andrea Di and Martin-Dussaud, Pierre},
  journal = {{Quantum}},
  issn = {2521-327X},
  publisher = {{Verein zur F{\"{o}}rderung des Open Access Publizierens in den Quantenwissenschaften}},
  volume = {6},
  pages = {826},
  month = oct,
  year = {2022}
}

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