Anomalous Weak Values and the Violation of a Multiple-measurement Leggett-Garg Inequality

Abstract

Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies, the so-called quantum technologies. The nonclassicality pointed out by Leggett-Garg inequalities has represented, with Bell inequalities, one of the most investigated subject. In this letter we study the connection of Leggett-Garg inequalities with a new emerging field of quantum measurement, the weak values. In particular, we perform an experimental study of the four-time correlators Legget-Garg test, by exploiting single and sequential weak measurements performed on heralded single photons. We show violation of a four-parameters Leggett-Garg inequality in different experimental conditions, demonstrating an interesting connection between Leggett-Garg inequality violation and anomalous weak values.

References in corpus (14)

• Ultrasensitive Beam Deflection Measurement via Interferometric Weak Value Amplification
• Research on Hidden Variable Theories: a review of recent progresses
• Complex weak values in quantum measurement
• Weak values and the Leggett-Garg inequality in solid-state qubits
• Anomalous Weak Values Are Proofs of Contextuality
• Macroscopicity of Mechanical Quantum Superposition States
• Ideal negative measurements in quantum walks disprove theories based on classical trajectories
• The conditions for quantum violation of macroscopic realism
• Sequential weak measurement
• Distinguishing quantum and classical transport through nanostructures
• Hardy's paradox and violation of a state-independent Bell inequality in time
• Comment on: How the result of a single coin toss can turn out to be 100 heads
• Improved implementation of nonclassicality test for a single particle
• Comment on 'How the result of a single coin toss can turn out to be 100 heads'