Entanglement by four wave mixing in atomic media

• Grant number: 18/20159-8
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2019
• End date: March 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Agreement: FACEPE
• Principal Investigator: Marcelo Martinelli
• Grantee: Marcelo Martinelli
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: José Wellington Rocha Tabosa ; Luciano Soares da Cruz ; Paulo Alberto Nussenzveig

Abstract

Parametric amplification is a powerful tool for the generation of entangled and squeezed states of the electromagnetic field. A revival of the interest for these states came on the last decade thanks to their potential applications in quantum information, with the use of cluster states for information processing.On the other hand, high levels of squeezing are on the verge of their application on the next run of the gravitational wave detector (LIGO collaboration), setting new goals for the generation and application of those states of the field.On this situation, the use of third order nonlinearities in four wave mixing process (4WM) allows the building of parametric amplifiers with very high gain, using optical field close to resonances of atomic media. Our laboratories are investigating the generation of entangled states in cold atoms, showing extreme gain ($>10^3$) for parametric amplification in a Cesium cloud, while extending this entanglement to four fields involved in this process. At USP, we are investigating entanglement in multiple fields coupled by hot rubidium vapors. At UFABC, the ultimate limit for squeezing with polarization self rotation are being achieved.This proposal involves the use of the complementary knowledge of the involved groups, exploring the different possibilities in quantum information, combining the knowledge of high control of atomic systems developed by the group at UFPE with the measurement techniques of the optical field developed in São Paulo. (AU)