Experimental Realization of Sequential Weak Measurements of Arbitrary Non-commuting Pauli Observables

TL;DR

This paper demonstrates the first experimental realization of sequential weak measurements of three non-commuting Pauli observables using single photons, advancing quantum measurement techniques and their applications.

Contribution

It introduces a method to perform arbitrary sequential weak measurements and experimentally demonstrates it with three non-commuting Pauli observables.

Findings

Successfully measured sequential weak values of three non-commuting observables

Enhanced understanding of quantum contextuality and uncertainty relations

Potential applications in quantum information processing

Abstract

Sequential weak measurements of non-commuting observables is not only fundamentally interesting in quantum measurement but also shown potential in various applications. The previous reported methods, however, can only realize limited sequential weak measurements experimentally. In this Letter, we propose the realization of sequential measurements of arbitrary observables and experimentally demonstrate for the first time the measurement of sequential weak values of three non-commuting Pauli observables by using genuine single photons. The results presented here will not only improve our understanding of quantum measurement, e.g. testing quantum contextuality, macroscopic realism, and uncertainty relation, but also have many applications such as realizing counterfactual computation, direct process tomography, direct measurement of the density matrix and unbounded randomness certification.