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Quantum optics using nanostructures: from many-body physics to quantum information processing (QON)
Date du début: 1 nov. 2008, Date de fin: 31 oct. 2013 PROJET  TERMINÉ 

"Spins in nanostructures have emerged as a new paradigm for studying quantum optical phenomena in the solid-state. Motivated by potential applications in quantum information processing, the research in this field has focused on isolating a single confined spin from its environment and implementing coherent manipulation. On the other hand, it has been realized that the principal decoherence mechanisms for confined spins, stemming from interactions with nuclear or electron spin reservoirs, are intimately linked to fascinating many-body condensed-matter physics. We propose to use quantum optical techniques to investigate physics of nanostructures in two opposite but equally interesting regimes, where reservoir couplings are either suppressed to facilitate coherent control or enhanced to promote many body effects. The principal focus of our investigation of many-body phenomena will be on the first observation of optical signatures of the Kondo effect arising from exchange coupling between a confined spin and an electron spin reservoir. In addition, we propose to study nonequilibrium dynamics of quantum dot nuclear spins as well as strongly correlated system of interacting polaritons in coupled nano-cavities. To minimize spin decoherence and to implement quantum control, we propose to use nano-cavity assisted optical manipulation of two-electron spin states in double quantum dots; thanks to its resilience against spin decoherence, this system should allow us to realize elementary quantum information tasks such as spin-polarization conversion and spin entanglement. In addition to indium/gallium arsenide based structures, we propose to study semiconducting carbon nanotubes where hyperfine interactions that lead to spin decoherence can be avoided. Our nanotube experiments will focus on understanding the elementary quantum optical properties, with the ultimate goal of demonstrating coherent optical spin manipulation."

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