Quantum probabilities from quantum entanglement: Experimentally unpacking the Born rule

TL;DR

This paper experimentally tests the envariance-based derivations of the Born rule, demonstrating quantum symmetries in entangled states and local systems, which could clarify the foundations of quantum probability.

Contribution

It provides experimental validation of envariance principles underlying the Born rule, advancing understanding of quantum probabilities from entanglement symmetries.

Findings

Confirmed envariance in entangled quantum states

Demonstrated envariance in local quantum systems

Supported derivations of the Born rule from quantum symmetries

Abstract

The Born rule, a foundational axiom used to deduce probabilities of events from wavefunctions, is indispensable in the everyday practice of quantum physics. It is also key in the quest to reconcile the ostensibly inconsistent laws of the quantum and classical realms, as it confers physical significance to reduced density matrices, the essential tools of decoherence theory. Following Bohr's Copenhagen interpretation, textbooks postulate the Born rule outright. However, recent attempts to derive it from other quantum principles have been successful, holding promise for simplifying and clarifying the quantum foundational bedrock. A major family of derivations is based on envariance, a recently discovered symmetry of entangled quantum states. Here, we identify and experimentally test three premises central to these envariance-based derivations, thus demonstrating, in the microworld, the symmetries from which the Born rule is derived. Further, we demonstrate envariance in a purely local quantum system, showing its independence from relativistic causality.