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arXiv · 0911.0330

Decoherence in a double-slit quantum eraser

F. A. Torres-Ruiz·G. Lima·A. Delgado·S. Pádua·C. Saavedra
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Abstract

We study and experimentally implement a double-slit quantum eraser in the presence of a controlled decoherence mechanism. A two-photon state, produced in a spontaneous parametric down conversion process, is prepared in a maximally entangled polarization state. A birefringent double-slit is illuminated by one of the down-converted photons, and it acts as a single-photon two-qubits controlled not gate that couples the polarization with the transversal momentum of these photons. The other photon, that acts as a which-path marker, is sent through a Mach-Zehnder-like interferometer. When the interferometer is partially unbalanced, it behaves as a controlled source of decoherence for polarization states of down-converted photons. We show the transition from wave-like to particle-like behavior of the signal photons crossing the double-slit as a function of the decoherence parameter, which depends on the length path difference at the interferometer.

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F. A. Torres-Ruiz, G. Lima, A. Delgado, S. Pádua, C. Saavedra. 2010-03-22. Decoherence in a double-slit quantum eraser. https://doi.org/10.1103/physreva.81.042104

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