Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum 2.0 Conference and Exhibition

Large-Scale Fiber Interferometry to Measure the Gravitationally Induced Phase Shift on Entangled Photons

E. Polini, Dorotea Macri, Xinghui Yin, Eric Glenn Oelker, Piotr T. Chruściel, Georgi Dvali, Christopher Hilweg, Mario Hudelist, Dorilian Lopez-Mago, Thomas Mieling, Thomas Morling, Marius A. Oancea, Raffaele Silvestri, Florian Steininger, Haocun Yu, Philip John Walther, N. Mavalvala

Published Jan 1, 2024• 2 citations
Publisher

Abstract

Gravitational time dilation, a prediction of General Relativity, lacks confirmation alongside quantum mechanics. Our experiment aims to measure gravitationally induced phase shift of path-entangled photons between two vertically displaced arms of a fiber interferometer.
DOI
10.1364/quantum.2024.qth4c.3

Related papers

High-Sensitivity Fiber Interferometer for Gravitational Phase Shift Measurement on Entangled States

E. Polini, Piotr T. Chruściel, Georgi Dvali +13 more

In this contribution, we describe the status of our experiment aimed at measuring the gravitationally induced phase shift on path-entangled photons. We use a kilometer-scale fiber interferometer whose arms are vertically displaced in the Earth gravitational potential, allowing photons propagating at different heights to accumulate different phases. To date, this is the first experiment to measure this effect on massless particles, thereby experimentally combining general relativity and quantum mechanics.

arXiv:2506.09770•Jun 11, 2025•0 citations

50-km fiber interferometer for testing gravitational signatures in quantum interference

Haocun Yu, Dorotea Macri, Thomas Morling +10 more

Quantum mechanics and general relativity are the foundational pillars of modern physics, yet experimental tests that combine the two frameworks remain rare. Measuring optical phase shifts of massless photons in a gravitational potential provides a unique quantum platform to probe gravity beyond Newtonian descriptions, but laboratory-based interferometers have not yet reached the sensitivity needed to access this regime. Here, we report the realization of a 50-km table-top Mach-Zehnder fiber interferometer operating at the single-photon level, achieving a phase sensitivity of $4.42\times10^{-6}$ rad root-mean-square (RMS) within the frequency range of 0.01 Hz to 5 Hz. We demonstrate that this sensitivity is sufficient to resolve a phase-shift signal of $(6.18 \pm 0.44)\times10^{-5}$ rad RMS at 0.1 Hz, associated with a modulated gravity-induced signal. Our results establish a milestone for quantum sensing with large-scale optical interferometry, demonstrating the capability to detect gravitational redshifts in a local laboratory, thereby paving the way for testing quantum phenomena within general relativistic frameworks.

quant-pharXiv:2511.17022•Physical Review Letters•Nov 24, 2025•2 citations

Probing Earth’s rotation effect on two-photon entanglement

Raffaele Silvestri, Haocun Yu, Robert W. Peterson +2 more

We present the first experimental measurement of the Earth’s rotation induced phase shift on a two-photon maximally entangled state by means of a large-scale fiber Sagnac interferometer of milliradian phase resolution.

Quantum 2.0 Conference and Exhibition•Jan 1, 2023•1 citation

Optimal Interferometer Geometry for Gravitationally Induced Quantum Entanglement

Alireza Maleki

The quest for a quantum theory of gravity remains a central challenge in modern physics, driven by the goal of unifying general relativity and quantum mechanics. Direct experimental access to quantum gravitational effects is notoriously difficult due to the inaccessibility of the Planck scale. Recent proposals, however, suggest that gravitationally induced quantum entanglement between two massive particles, realized through advanced quantum interferometric techniques, could provide empirical evidence for the quantum nature of gravity. We demonstrate that the geometrical configuration of an interferometer plays a decisive role in entanglement generation. Our analysis reveals that geometric optimization can substantially enhance the gravitationally induced phase shift, thereby improving the prospects for experimental detection of gravity-mediated entanglement. Moreover, we show that standard approximations employed in prior proposals may severely limit predictive accuracy and compromise experimental feasibility.

quant-pharXiv:2610.04471•Oct 6, 2026•0 citations

Operational Measurement of Open-Path Gravitational Phases via Local Homodyne Tomography in Large-Scale Fiber Interferometry

m el-rakhawi

Operational Measurement of Open-Path Gravitational Phases via Local Homodyne Tomography in Large-Scale Fiber Interferometry

•Jul 25, 2026•0 citations

Gravitational redshift in quantum-clock interferometry

Albert Roura

Remarkable advances in atom interferometry have enabled the creation of macroscopically delocalized quantum superpositions with atomic wave packets separated up to half a meter. Nevertheless, in all cases realized so far the differences in the dynamics of the two wave packets of the superposition can be entirely described in terms of Newtonian mechanics. Therefore, the creation of delocalized coherent superpositions of quantum systems experiencing different relativistic effects is an important milestone in future research at the interface of gravity and quantum mechanics. This could be achieved by generating a superposition of quantum clocks that follow paths with different gravitational time dilation and investigating the consequences on the interference signal when they are eventually recombined. After explaining the major challenges that quantum-clock interferometry based on light-pulse atom interferometers is confronted with (including their insensitivity to gravitational redshift in a uniform field), I will present a promising scheme capable of measuring the effects of gravitational time dilation in interfering quantum clocks. Its experimental implementation should be within reach of the 10-meter atomic fountains of Sr and Yb atoms that will soon become available in Stanford and HITec (Hanover) respectively.

•Jan 1, 2021•72 citations
In this contribution, we describe the status of our experiment aimed at measuring the gravitationally induced phase shift on path-entangled photons. We use a kilometer-scale fiber interferometer whose arms are vertically displaced in the Earth gravitational potential, allowing photons propagating at different heights to accumulate different phases. To date, this is the first experiment to measure this effect on massless particles, thereby experimentally combining general relativity and quantum mechanics.
Quantum mechanics and general relativity are the foundational pillars of modern physics, yet experimental tests that combine the two frameworks remain rare. Measuring optical phase shifts of massless photons in a gravitational potential provides a unique quantum platform to probe gravity beyond Newtonian descriptions, but laboratory-based interferometers have not yet reached the sensitivity needed to access this regime. Here, we report the realization of a 50-km table-top Mach-Zehnder fiber interferometer operating at the single-photon level, achieving a phase sensitivity of 4.42×10−64.42\times10^{-6}4.42×10−6 rad root-mean-square (RMS) within the frequency range of 0.01 Hz to 5 Hz. We demonstrate that this sensitivity is sufficient to resolve a phase-shift signal of (6.18±0.44)×10−5(6.18 \pm 0.44)\times10^{-5}(6.18±0.44)×10−5 rad RMS at 0.1 Hz, associated with a modulated gravity-induced signal. Our results establish a milestone for quantum sensing with large-scale optical interferometry, demonstrating the capability to detect gravitational redshifts in a local laboratory, thereby paving the way for testing quantum phenomena within general relativistic frameworks.
The quest for a quantum theory of gravity remains a central challenge in modern physics, driven by the goal of unifying general relativity and quantum mechanics. Direct experimental access to quantum gravitational effects is notoriously difficult due to the inaccessibility of the Planck scale. Recent proposals, however, suggest that gravitationally induced quantum entanglement between two massive particles, realized through advanced quantum interferometric techniques, could provide empirical evidence for the quantum nature of gravity. We demonstrate that the geometrical configuration of an interferometer plays a decisive role in entanglement generation. Our analysis reveals that geometric optimization can substantially enhance the gravitationally induced phase shift, thereby improving the prospects for experimental detection of gravity-mediated entanglement. Moreover, we show that standard approximations employed in prior proposals may severely limit predictive accuracy and compromise experimental feasibility.
Remarkable advances in atom interferometry have enabled the creation of macroscopically delocalized quantum superpositions with atomic wave packets separated up to half a meter. Nevertheless, in all cases realized so far the differences in the dynamics of the two wave packets of the superposition can be entirely described in terms of Newtonian mechanics. Therefore, the creation of delocalized coherent superpositions of quantum systems experiencing different relativistic effects is an important milestone in future research at the interface of gravity and quantum mechanics. This could be achieved by generating a superposition of quantum clocks that follow paths with different gravitational time dilation and investigating the consequences on the interference signal when they are eventually recombined. After explaining the major challenges that quantum-clock interferometry based on light-pulse atom interferometers is confronted with (including their insensitivity to gravitational redshift in a uniform field), I will present a promising scheme capable of measuring the effects of gravitational time dilation in interfering quantum clocks. Its experimental implementation should be within reach of the 10-meter atomic fountains of Sr and Yb atoms that will soon become available in Stanford and HITec (Hanover) respectively.