On the Testability of the Equivalence Principle as a Gauge Principle Detecting the Gravitational t3 Phase
Frontiers in Physics Frontiers 8 (2020) 176
Information fluctuation theorem for an open quantum bipartite system.
Physical review. E 101:5-1 (2020) 052128
Abstract:
We study an arbitrary nonequilibrium dynamics of a quantum bipartite system coupled to a reservoir. For its characterization, we present a fluctuation theorem (FT) that explicitly addresses the quantum correlation of subsystems during the thermodynamic evolution. To our aim, we designate the local and the global states altogether in the time-forward and the time-reversed transition probabilities. In view of the two-point measurement scheme, only the global states are subject to measurements whereas the local states are used only as an augmented information on the composite system. We specifically derive a FT in such a form that relates the entropy production of local systems in the time-forward transition to the change of quantum correlation in the time-reversed transition. This also leads to a useful thermodynamic inequality and we illustrate its advantage by an example of an isothermal process on Werner states.Witnesses of non-classicality for simulated hybrid quantum systems
Journal of Physics Communications IOP Publishing 4:2 (2020) 025013
Abstract:
The task of testing whether quantum theory applies to all physical systems and all scales requires considering situations where a quantum probe interacts with another system that need not obey quantum theory in full. Important examples include the cases where a quantum mass probes the gravitational field, for which a unique quantum theory of gravity does not yet exist, or a quantum field, such as light, interacts with a macroscopic system, such as a biological molecule, which may or may not obey unitary quantum theory. In this context a class of experiments has recently been proposed, where the non-classicality of a physical system that need not obey quantum theory (the gravitational field) can be tested indirectly by detecting whether or not the system is capable of entangling two quantum probes. Here we illustrate some of the subtleties of the argument, to do with the role of locality of interactions and of non-classicality, and perform proof-of-principle experiments illustrating the logic of the proposals, using a Nuclear Magnetic Resonance quantum computational platform with four qubits.Different instances of time as different quantum modes: quantum states across space-time for continuous variables
New Journal of Physics IOP Publishing 22:2 (2020) 023029
Non-Monogamy of Spatio-Temporal Correlations and the Black Hole Information Loss Paradox.
Entropy (Basel, Switzerland) 22:2 (2020) E228