For the weak equivalence principle (WEP) to hold, we should not be able to gain any information about mass from its interaction with gravitational fields. This motivates the use of information theoretic techniques to investigate WEP violation. Using this approach, we demonstrate that the WEP holds for a quantum particle in a uniform gravitational field, but is violated in non-uniform and time-dependent gravitational fields, such as in gravitational waves. This provides a precise characterization ofWEP violation by quantum systems in gravitational fields, that should be useful in formalizing other works that have argued for such violations heuristically. In particular, we discuss the possibility of detecting the gravitational Casimir effect with superconductors from an information theoretic perspective.

We will use Fisher information to properly analyze the quantum weak equivalence principle. We argue that gravitational waves will be partially reflected by superconductors. This will occur as the violation of the weak equivalence principle in Cooper pairs is larger than the surrounding ionic lattice. Such reflections of virtual gravitational waves by superconductors can produce a gravitational Casimir effect, which may be detected using currently available technology.