Speaker
Description
The most precise measurements of the acceleration due to gravity, g, of atoms are performed using the techniques of atom interferometry [1]. In general these approaches rely on the preparation of translationally cold samples of ground-state atoms and are therefore at present challenging to implement for tests of the Weak Equivalence Principle (WEP) with neutral antimatter - in particular positronium with its short ground-state annihilation lifetime of 142 ns. To address these challenges, we have developed a method to perform atom interferometry with samples in high Rydberg states [2,3]. This is an electric analogue of magnetic Stern-Gerlach interferometry [4]. In this approach, we prepare atoms in coherent superpositions of Rydberg states with different static electric dipole moments - or Stark shifts - and use inhomogeneous electric fields to apply state-dependent forces on them. This leads to the coherent generation of spatially separated atomic momentum states that can be exploited for interferometry and measurements of g. In this talk, I will describe these experimental techniques and their application to coherently prepare helium Rydberg atoms in spatially separated momentum states. I will show how this approach can be adapted to measure g for Rydberg helium atoms, and ultimately employed in tests of the WEP with long-lived Rydberg positronium [4].
[1] A. Peters, K. Y. Chung and S. Chu, Metrologia 38, 25 (2001)
[2] J. E. Palmer and S. D. Hogan, Phys. Rev. Lett. 122, 250404 (2019)
[3] J. D. R. Tommey and S. D. Hogan, Phys. Rev. A 104, 033305 (2021)
[4] Y. Margalit, O. Dobkowski, Z. Zhou, O. Amit, Y. Japha, S. Moukouri, D. Rohrlich, A. Mazumdar, S. Bose, C. Henkel and R. Folman, Sci. Adv. 7, eabg2879 (2021)
[5] A. Deller, A. M. Alonso, B. S. Cooper, S. D. Hogan and D. B. Cassidy, Phys. Rev. A 93, 062513 (2016)
