Is wave-particle objectivity compatible with determinism and locality?

TL;DR

This paper investigates whether wave-particle objectivity can coexist with determinism and locality in quantum mechanics, showing that all three conditions cannot simultaneously hold when tested with entanglement-assisted experiments.

Contribution

It extends hidden-variable theories to include controlling devices and demonstrates the incompatibility of wave-particle objectivity, determinism, and locality under entanglement.

Findings

All three conditions are incompatible when combined with entanglement.

The contradiction persists for any non-zero entanglement.

Proposes an experiment to empirically test these theoretical conclusions.

Abstract

Wave-particle duality, superposition and entanglement are among the most counterintuitive features of quantum theory. Their clash with our classical expectations motivated hidden-variable (HV) theories. With the emergence of quantum technologies we can test experimentally the predictions of quantum theory {\em versus} HV theories and put strong restrictions on their key assumptions. Here we study an entanglement-assisted version of the quantum delayed-choice experiment and show that the extension of HV to the controlling devices only exacerbates the contradiction. We compare HV theories that satisfy the conditions of objectivity (a property of photons being either particles or waves, but not both), determinism, and local independence of hidden variables with quantum mechanics. Any two of the above conditions are compatible with it. The conflict becomes manifest when all three conditions are imposed and persists for any non-zero value of entanglement. We propose an experiment to test our conclusions.