Violation of the Equivalence Principle for some Macroscopic Quantum Bodies

We consider macroscopic ensembles of the hydrogen atoms in a weak post-Newtonian gravitation field in the presence of quantum effects. We show that for the most ensembles the Einstein’s Equivalence Principle is valid in the above mentioned quantum case. On the other hand, it is shown to be broken for some special macroscopic ensembles [1] – the coherent quantum superpositions of the stationary quantum states. We discuss how such ensembles (which we call “Gravitational demons”) can be created using laser technique in the Earth’s laboratories and how the violation of the Equivalence Principle can be observed.

[1] A.G. Lebed, Editor, Breakdown of Einstein’s Equivalence Principle (World Scientific, Singapore, 2023).