First-principle approach to the superpositions of gravitational fields in atom interferometry

Understanding the fundamental nature of gravity at the interface with quantum theory is a major open question in theoretical physics. Recent progress in experiments has enabled probing the interaction of quantum particles with gravitational fields beyond the uniform-field regime. To obtain a logically consistent conceptual framework for quantum systems that gravitate, it is then interesting to assess what current experiments can conclude on the nature of gravity with additional assumptions on the physical theory. In particular, I will discuss a recent gravitational Aharonov-Bohm experiment [Overstreet, Asenbaum, Curti, Kim, Kasevich, Science, 375 (6577) 2022] under three assumptions: 1. Existence of gravitational fields, 2. Field-energy principle, 3. Quantum Relativity Principle. I will show that, provided that these assumptions are valid, the setup of the gravitational Aharonov-Bohm experiment is equivalent to one in which the source of the gravitational field is in a quantum superposition. Key to this argument is the validity of the laws of physics in arbitrary quantum reference frames, namely reference frames associated to quantum systems.

Zoom link:  https://pitp.zoom.us/j/93404802249?pwd=UU1Wdml4c2FnRW9aQVp1NzFTTHhPUT09