Correlating Local Quantum Reality with Causally Disconnected Choices

Abstract

In 1935, Einstein, Podolsky, and Rosen (EPR) claimed the incompleteness of quantum mechanics based on the notions of realism (``{\it If, without in any way disrupting a system, we can predict with certainty - i.e., with a probability of one - the value of a physical quantity, then an element of physical reality corresponds to this physical quantity.}'') and locality (``{\it ...\,since the two systems no longer interact, no real change can take place in the second system in consequence of anything that may be done to the first system}''). EPR also insisted that ``{\it The elements of physical reality cannot be determined by \emph{a priori} philosophical considerations, but must be found by\,...\,experiments and measurements.}''. Here, employing an operational framework for testing realism in quantum systems, we envisage an experiment -- referred to as the Reality Quantum Correlator (RQC) -- capable of showing that the elements of reality in one laboratory can be correlated with causally disconnected choices, thus questioning EPR's locality. Empirical evidence supporting our theoretical predictions is then provided by implementing the corresponding quantum circuit on IBM's quantum computers.