Observations of the delayed-choice quantum eraser using coherent photons

TL;DR

This paper experimentally demonstrates a delayed-choice quantum eraser using coherent photons, highlighting the violation of cause-effect relations through basis selection in a Mach-Zehnder interferometer.

Contribution

It introduces a novel experimental setup for the quantum eraser with coherent photon pairs and delayed basis choice, advancing understanding of quantum complementarity.

Findings

Violation of cause-effect relation demonstrated

Quantum eraser achieved with coherent photons

Basis choice influences interference patterns

Abstract

Quantum superposition is the cornerstone of quantum mechanics, where interference fringes originate in the self-interference of a single photon via indistinguishable photon characteristics. Wheeler delayed-choice experiments have been extensively studied for the wave-particle duality over the last several decades to understand the complementarity theory of quantum mechanics. The heart of the delayed-choice quantum eraser is in the mutually exclusive quantum feature violating the cause-effect relation. Here, we experimentally demonstrate the quantum eraser using coherent photon pairs by the delayed choice of a polarizer placed out of the interferometer. Coherence solutions of the observed quantum eraser are derived from a typical Mach-Zehnder interferometer, where the violation of the cause-effect relation is due to selective measurements of basis choice.