We develop a setup suitable for cavity enhanced levitated atom interferometer which is capable of interaction times of several seconds  and for investigating interactions between atoms and electrons (the Quantum Klystron, ). Atom interferometry enables high precision experiments allowing for search for new physics [3, 4]. The Quantum Klystron mimics electromagnetic radiation by the non-radiating near-field of a density modulated electron beam to coherently manipulate atoms in the |F = 1⟩ and |F = 2⟩ hyperfine groundstates. The experiment consists of a transfer chamber separated by a valve to a science chamber, which facilitates the exchange of the electron beam source. This also offers the possibility to insert samples, e.g. test masses, and measure their effect on the potassium atoms for further interferometry experiments.
-  V. Xu, M. Jaffe, C. D. Panda, S. L. Kristensen, L. W. Clark, H. Mu ̈ller, “Probing gravity by holding atoms for 20 seconds”, Science 366, 745 (2019).
-  D. Ra ̈tzel, D. Hartley, O. Schwartz, and P. Haslinger. (2020). “A Quantum Klystron – Controlling Quantum Systems with Modulated Electron Beams”, ArXiv:2004.10168.
-  P. Hamilton, M. Jaffe, P. Haslinger, Q. Simmons, H. Mu ̈ller, J. Khoury, “Atom- interferometry constraints on dark energy”, Science 349, 849 (2015).
-  R. H. Parker, C. Yu, W. Zhong, B. Estey, and H. Mu ̈ller, Measurement of the fine- structure constant as a test of the Standard Model, Science 360, 191 (2018).