Quantum properties of macroscopic states of light

• Grant number: 10/19486-2
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2011
• Effective date (End): March 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Marcelo Martinelli
• Grantee: Alessandro de Sousa Villar
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In future implementations of quantum networks, light will be the most adequate physical carrier of non-classicality. The optical parametric oscillator (OPO) stands as one of the most important devices to produce light with genuine quantum properties. Those properties are investigated by the host research group in the regime where the three interacting beams possess macroscopic intensities. This research project follows those lines of investigation, in which one tries to better understand multipartite entangled states produced by the OPO and harness their special power in applications. In particular, part of this investigation relies on understanding the spectral structure of such intense light beams: to determine the quantum states of the three beams also in the spectral region where stimulated emission takes place. This project aims at extending the knowledge about the quantum properties of intense light beams to their most energetic spectral regions, characterized by “macroscopic” states of light. In this way, we will try to reconcile conflicting visions about the classicality of such modes. On one hand, intense beams must show continuous energy by the correspondence principle, but on the other they must be produced by the same dynamics leading to multipartite entanglement. We expect our investigations to bring us one step closer to the solution of an old enigma: how the transition between quantum and classical domains take place and where the boundary is located.