Experimental Test of Born's Rule by Inspecting Third-Order Quantum Interference on a Single Spin in Solids

TL;DR

This experiment tests Born's rule by measuring third-order quantum interference in a single spin in diamond, finding no significant deviation and thus supporting the rule's validity.

Contribution

The study provides the first experimental test of third-order quantum interference in a solid-state system, setting stringent limits on potential violations of Born's rule.

Findings

Third-order interference ratio ceiled at 10^{-3}

No evidence of Born's rule violation

Supports the fundamental postulate of quantum mechanics

Abstract

As a fundamental postulate of quantum mechanics, Born's rule assigns probabilities to the measurement outcomes of quantum systems and excludes multi-order quantum interference. Here we report an experiment on a single spin in diamond to test Born's rule by inspecting the third-order quantum interference. The ratio of the third-order quantum interference to the second-order in our experiment is ceiled at the scale of $10^{-3}$, which provides a stringent constraint on the potential breakdown of Born's rule.