Measuring gravitational time dilation with delocalized quantum superpositions

authored by

Albert Roura, Christian Schubert, Dennis Schlippert, Ernst M. Rasel

Abstract

Atomic clocks can measure the gravitational redshift predicted by general relativity with great accuracy and for height differences as little as 1 cm. All existing experiments, however, involve the comparison of two independent clocks at different locations rather than a single clock in a delocalized quantum superposition. Here we present an interferometry scheme employing group-II-type atoms, such as Sr or Yb, capable of measuring the gravitational time dilation in a coherent superposition of atomic wave packets at two different heights. In contrast to other recent proposals, there is no need for pulses that can efficiently diffract both internal states. Instead, the scheme relies on very simple atom optics for which high-diffraction efficiencies can be achieved with rather mild requirements on laser power. Furthermore, the effects of vibration noise are subtracted by employing a simultaneous Rb interferometer that acts as an inertial reference. Remarkably, the recently commissioned VLBAI facility in Hannover, a 10-meter atomic fountain that can simu ltaneously operate Yb and Rb atoms and enables up to 2.8 s of free evolution time, meets all the requirements for a successful experimental implementation.

Organisation(s)

Institute of Quantum Optics
QuantumFrontiers
CRC 1227 Designed Quantum States of Matter (DQ-mat)

External Organisation(s)

German Aerospace Center (DLR)
DLR-Institute for Satellite Geodesy and Inertial Sensing

Type

Article

Journal

Physical Review D

Volume

104

ISSN

2470-0010

Publication date

01.10.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

Electronic version(s)

https://arxiv.org/abs/2010.11156 (Access: Open)
https://doi.org/10.1103/PhysRevD.104.084001 (Access: Open)