Progress toward tests of gravity and quantum mechanics using atom interferometry with Strontium

Following recent developments in light-pulse atom interferometry (AI) [1], the ability to perform sufficiently sensitive measurements of gravitational effects have opened a window into exploring novel fundamental physics. For example, investigation of the gravitational forces at the 0.1-1 meter distance scale using AI [2] has the potential to reveal violations of the gravitational inverse square law, study the gravitational Aharonov-Bohm effect, and test theories of gravity-induced quantum decoherence; these research topics are the focus of the atomic fountain (AF) described in this work.

In this talk, I will provide recent technical updates on the construction of a 2 meter baseline AF using ultracold Strontium (Sr). First, I will review the architecture of the laser system required to laser cool (1 mK) and trap the Sr atoms and perform AI using a two-photon Bragg transition at 461 nm. Second, I will review our progress on the installation of the ultrahigh vacuum system of the AF. Finally, I will present an example of how we plan to use micron-precision translation stages to measure gravity from well-characterized test source masses in the 100-1000 kg range.

[1] Kovachy et al. (2015). Nature 528, 530

[2] Asenbaum et al. (2017). Phys. Rev. Lett. 118, 183602