Abstract
The microscopic theory of superconductivity raised the disruptive idea that electrons couple through the elusive exchange of virtual phonons, overcoming the strong Coulomb repulsion to form Cooper pairs. Light is also known to interact with atomic vibrations, as, for example, in the Raman effect. We show that photon pairs exchange virtual vibrations in transparent media, leading to an effective photon-photon interaction identical to that for electrons in the BCS theory of superconductivity, in spite of the fact that photons are bosons. In this scenario, photons may exchange energy without matching a quantum of vibration of the medium. As a result, pair correlations for photons scattered away from the Raman resonances are expected to be enhanced. An experimental demonstration of this effect is provided here by time-correlated Raman measurements in different media. The experimental data confirm our theoretical interpretation of a photonic Cooper pairing, without the need for any fitting parameters.
- Received 11 August 2017
DOI:https://doi.org/10.1103/PhysRevLett.119.193603
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Photons Couple Like Cooper Pairs
Published 9 November 2017
A pairing of photons—similar to the pairing of electrons in superconductors—can occur when light scatters in a transparent medium.
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