Impact of parity violation on quantum entanglement and Bell nonlocality

Abstract We present our new findings on how various fundamental interactions decisively shape quantum entanglement and the Bell measure within and beyond the quantum field theory (QFT). In QFT, parity symmetry plays a key role in determining entanglement. Parity-conserving interactions produce maximally entangled bipartite systems, while maximally parity-violating interactions result in disentangled bipartite systems, placing the Bell measure on the boundary between classical and quantum theories. By examining the relation between quantum entanglement and Bell measure, we find that clean signals for interactions beyond QFT may be obtained. We propose methods to test these potential signals. Furthermore, we highlight the previously overlooked influence of magnetic fields within detectors, which radically alters predictions for quantum entanglement and Bell nonlocality. This environmental effect induces spurious P and charge-parity (CP) violations, which has to be carefully accounted for to reveal the true P, CP, and Bell nonlocality effects.