44 research outputs found
High efficiency quantum memory for the implementation quantum information protocols
L'objectif de ce travail de thĂšse est de mettre en Ćuvre une mĂ©moire quantique de haute efficacitĂ© dans le cadre dâun protocole de gĂ©nĂ©ration d'Ă©tats quantiques de la lumiĂšre, avec pour finalitĂ© une augmentation de plusieurs ordres de grandeur du taux de gĂ©nĂ©ration de ces Ă©tats. Nous montrons comment une telle architecture peut ĂȘtre utilisĂ©e en pratique pour la gĂ©nĂ©ration dâĂ©tats clĂ©s pour lâoptique quantique, tels que les Ă©tats "chats de Schrödinger optiques" (superposition quantique dâĂ©tats cohĂ©rents de phases opposĂ©es) qui sont une brique de base pour de nombreux protocoles dans le domaine de lâinformation quantique. Nous rĂ©alisons cette mĂ©moire Ă lâaide dâune cavitĂ© optique de haut facteur de qualitĂ©, un dispositif actif permettant dâinsĂ©rer et dâextraire une impulsion lumineuse Ă la demande, et nous lâalimentons avec des photons uniques issus dâune source rapide en cavitĂ© optique synchronisĂ©e. La mise en Ćuvre dâune telle mĂ©moire nĂ©cessite une connaissance complĂšte des paramĂštres physiques, et notamment de la phase des Ă©tats quantiques, menant Ă la mise en place dâoutils de diagnostics prĂ©cis. Il sâagit lĂ dâun premier pas vers la manipulation en temps rĂ©el dâĂ©tats encodĂ©s sur la lumiĂšre en espace libre.The aim of this thesis work is to implement a high efficiency quantum memory as part of a generation protocol for quantum states of light, targeting an increase of the generation rate by several orders of magnitude. We show how such an architecture can be used in practice for the generation of key states for quantum optics, as the "optical Schrödinger cat states" (quantum superposition of coherent states with opposite phases) which are an elementary piece for numerous protocols in the field of quantum information. We implement this memory with a high finesse optical cavity, an active device allowing to store/extract a light pulse on demand, and we feed it with single photons from a high-rate source in a synchronized optical cavity. The use of such memory requires a complete knowledge of the physical parameters, such as the phase of the generated quantum states. This led us to develop accurate diagnostic tools. This constitutes a first step towards the real-time manipulation of states encoded on free-propagating light
Mémoire quantique de haute efficacité pour la mise en oeuvre de protocoles d'information quantique
The aim of this thesis work is to implement a high efficiency quantum memory as part of a generation protocol for quantum states of light, targeting an increase of the generation rate by several orders of magnitude. We show how such an architecture can be used in practice for the generation of key states for quantum optics, as the "optical Schrödinger cat states" (quantum superposition of coherent states with opposite phases) which are an elementary piece for numerous protocols in the field of quantum information. We implement this memory with a high finesse optical cavity, an active device allowing to store/extract a light pulse on demand, and we feed it with single photons from a high-rate source in a synchronized optical cavity. The use of such memory requires a complete knowledge of the physical parameters, such as the phase of the generated quantum states. This led us to develop accurate diagnostic tools. This constitutes a first step towards the real-time manipulation of states encoded on free-propagating light.L'objectif de ce travail de thĂšse est de mettre en Ćuvre une mĂ©moire quantique de haute efficacitĂ© dans le cadre dâun protocole de gĂ©nĂ©ration d'Ă©tats quantiques de la lumiĂšre, avec pour finalitĂ© une augmentation de plusieurs ordres de grandeur du taux de gĂ©nĂ©ration de ces Ă©tats. Nous montrons comment une telle architecture peut ĂȘtre utilisĂ©e en pratique pour la gĂ©nĂ©ration dâĂ©tats clĂ©s pour lâoptique quantique, tels que les Ă©tats "chats de Schrödinger optiques" (superposition quantique dâĂ©tats cohĂ©rents de phases opposĂ©es) qui sont une brique de base pour de nombreux protocoles dans le domaine de lâinformation quantique. Nous rĂ©alisons cette mĂ©moire Ă lâaide dâune cavitĂ© optique de haut facteur de qualitĂ©, un dispositif actif permettant dâinsĂ©rer et dâextraire une impulsion lumineuse Ă la demande, et nous lâalimentons avec des photons uniques issus dâune source rapide en cavitĂ© optique synchronisĂ©e. La mise en Ćuvre dâune telle mĂ©moire nĂ©cessite une connaissance complĂšte des paramĂštres physiques, et notamment de la phase des Ă©tats quantiques, menant Ă la mise en place dâoutils de diagnostics prĂ©cis. Il sâagit lĂ dâun premier pas vers la manipulation en temps rĂ©el dâĂ©tats encodĂ©s sur la lumiĂšre en espace libre
Experimental generation of coherent-state superpositions with a quantum memory
We implement an iterative scheme for the generation of coherent states superpositions, using a quantum memory to take advantage of the iterative nature of the protocol. The generation rate has thus been increased by one order of magnitude, reaching 100 (Hz). Furthermore, the generated states were stored in the quantum memory during 184 (ns) before their characterization, paving the way toward the implementation of more complex iterative protocols
An all-optical quantum processor for iterative generation of quantum states
International audienceIterative schemes have a great potential for efficient production of complex quantum states of light. This concept refers to generation protocols working on a set of quantum states, starting from basic resources as single-photon states, and building the target in several steps through the implementation of simple quantum operations on the intermediate states. This constitutes a quantum algorithm and requires a basic quantum processor. In this talk we will discuss all-optical architectures for that purpose, based on optical cavities and fast optical switches coupled to a fast-rate single photon source
An all-optical quantum processor for iterative generation of quantum states
International audienceIterative schemes have a great potential for efficient production of complex quantum states of light. This concept refers to generation protocols working on a set of quantum states, starting from basic resources as single-photon states, and building the target in several steps through the implementation of simple quantum operations on the intermediate states. This constitutes a quantum algorithm and requires a basic quantum processor. In this talk we will discuss all-optical architectures for that purpose, based on optical cavities and fast optical switches coupled to a fast-rate single photon source
Cavities and Quantum Memories for engineering of non-classical states of light (Orale)
International audienc