Temporal steering in four dimensions with applications to coupled qubits and magnetoreception

Abstract

Einstein--Podolsky--Rosen (EPR) steering allows Alice to remotely prepare a state in some specific bases for Bob through her choice of measurements. The temporal analog of EPR steering, temporal steering, also reveals the steerability of a single system between different times. Focusing on a four-dimensional system, here we investigate the dynamics of the temporal steering measures, the temporal steering robustness, using five mutually unbiased bases. As an example of an application, we use these measures to examine the temporal correlations in a radical pair model of magnetoreception. We find that, due to interactions with a static nuclear spin, the radical pair model exhibits strong non-Markovianity.