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Multiple approaches for multimode quantum memories

Periodic Report Summary 1 - MULTIMEM (Multiple approaches for multimode quantum memories.)

Since February 2012, Quentin Glorieux worked as a post-doctoral researcher at NIST in the group, led by William D. Phillips is internationally recognized for its expertise in the field of ultra-cold atoms. Within the group, Paul Lett has developed a research topic in quantum optics, on the generation of squeezed states of the field using the four-wave mixing. Quentin Glorieux joined the team and is involved in several theoretical and experimental projects.
Quentin Glorieux has worked on two experimental areas.
On the one hand, a continuation of his thesis, he studied the generation of quantum states spatial multimode four-wave mixing and secondly it has developed a new area of research around the use of these states to carry out experiments of innovative quantum optics.
We got many great results that have been the subject of a publication or are in the process of being. These include the demonstration of continuous variable entanglement in the pulse-type diet and optimizing the level of quantum correlations generation to -10.2 dB below the standard quantum limit. We have also demonstrated the possibility of using quantum correlation between two twin beams for imaging an object using only the properties of the quantum noise of light. Also we used these states to study the "discord" quantum and impact of losses on multimode conflicting statements. More recently, we demonstrated that it was possible to use these states to generate two streams of correlated random numbers. Finally we studied the possibility of spreading such entangled media with a negative index of group states. In these environments, it is possible to propagate a pulse at a rate of greater than c group, and we have demonstrated that quantum correlations in a range of frequencies around 1 MHz could be preserved, which is the first demonstration of a quantum effect for this type of environments.
Meanwhile, Quentin Glorieux led theoretical work in collaboration with Alberto Marino. This collaboration has demonstrated the interest of multimode squeezed states sources for quantum imaging techniques.
Quantum Memory
The project is based on the development of quantum memory in different media (steam, cold atoms, crystals) ordinates by the task Nicolas Gisin at the University of Geneva and in partnership with two international research groups: the group with Paul Lett University of Maryland and the group of Ping Koy Lam Australian National University.
Quantum memory in a hot steam - University of Maryland (UMD), College Park
Initially, Quentin Glorieux built at the University of Maryland a new experience to disassemble a quantum memory in an atomic vapor. The technique used is based on the gradient echo protocol. In this experiment, we demonstrated the coherent storage of two consecutive images, that is to say, the first demonstration of a multiplexing to both temporal and spatial in an atomic memory. Similarly, we have introduced new tools for quantum optics multimode demonstrating proofreading (and deletion) of subregions stored in an atomic dump. Finally the second stage of this experiment was to combine a multimode squeezed states source (4-wave mixing) with our memory to store images and demonstrate the intricate nature of our quantum memory.