Einstein-Podolsky-Rosen Steering in Quantum Theory and Beyond
Quantum entanglement manifests itself in various different ways, with its most striking consequence being non-locallty. In recent years, non-locality as a generic phenomenon has been studied independently of the formalism of quantum theory by treating processes as black boxes that produce statistics. Another consequence of entanglement is Einstein-Podolsky-Rosen (EPR) Steering, where one party, Bob, is assumed to have a quantum system and another party, Alice, can produce classical information to try and convince Bob that they shared an entangled quantum state all along; this is done by demonstrating EPR Steering. One cannot study this phenomenon completely independently of quantum theory since one party is assumed to be in possession of a quantum system. However, I will argue that we can still try and use EPR Steering to probe beyond quantum theory in novel ways. I will go on to discuss a methodical approach for the study of Post-quantum Steering using quantum channels and some simple pictorial reasoning.