Entangled photons from disordered systems

• Grant number: 25/04954-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: May 01, 2025
• End date: February 28, 2030
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Romain Pierre Marcel Bachelard
• Grantee: João Vítor dos Santos Ferreira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 22/00209-6 - Second generation quantum technologies, AP.TEM

Abstract

The interactions in disordered systems lead to 'random' new spectral lines, since the energy shifts depend on the specific distance between the atoms. Nevertheless, in the case of dipole-dipole interactions, it is worth noting that the fully excited state does not possess a shift. The PhD candidate will investigate the emission of correlated photons from disordered clouds, with a particular focus on the resonant-driving case. Indeed, this absence of shift means that the knowledge of the atomic configurations is not necessary to address this state specifically. The entanglement will be studied for photons of different colors and directions, by considering a collection of frequency-resolved detectors. Starting with the simple case of a pair of atoms, the student will investigate how the emission of correlated photons is possible with strongly interacting atoms, and how these correlations are affected by the distance (and thus the interaction strength) of the particles. The next step will be to generalize the result to a few quantum emitters, and to understand the critical parameters to achieve several-photon entanglement. Finally, the student will investigate how specific interference effects, such as localization effects, can affect this effect. (AU)