High-Fidelity, Long-Term Coherent Memory with Bose-Einstein Condensates for Implementation of Quantum Repeater Architectures

点击翻译按钮获取中文摘要

In the laboratory of the PI, light pulses are stored for 1.5 seconds in a coherent optical memory formed by a Bose-Einstein condensate. In the experiments, a light pulse is injected into the BEC, where it is converted to a matter imprint. Atom interactions in the condensate are manipulated with use of magnetic fields, and the system enters a phase separating regime: much like oil and water separate, the created matter imprint digs a hole for itself in the host condensate. The imprint is nestled in this void and avoids collisions with condensate atoms, thereby minimizing losses. As a result, the matter imprint can be stored over extended time scales. The imprint is then moved to the outer tip of the condensate where it is converted back to light, and, from this location, the light pulse exits the condensate with minimal loss. With optimization of the atom-trap design and optical storage mechanism, the efficiency for optical imprinting and retrieval is being increased ten-fold, and the storage time for the matter imprint is being extended to the one-minute regime. Such observations represent a milestone and will allow for entanglement distribution with quantum repeaters over distances well beyond what can be achieved with optical pulses and direct fiber coupling. Actual construction of a prototype quantum repeater setup is being carried out and the performance will be tested by Bell measurements. The results have important applications for creation of long-distance quantum networks for distributed quantum computing, teleportation, and cryptography for secure data transfer.In this project, the extreme manipulation of light is achieved and is being utilized for powerful optical information processing. The experiments are based on slowed and stopped light in ultra-cold Bose-Einstein condensates. Light pulses are injected into a condensate, where they are slowed and spatially compressed by factors of 100 millions, then extinguished and converted to matter copies. A resulting matter copy can easily be manipulated with lasers and magnetic fields, and can be stored over extended time scales: for seconds and even minutes. This is long enough for light -- under normal circumstances -- to travel back and forth to the Moon. The achieved storage times and control over the matter imprints have important applications for creation of entangled states of light and matter and for creation of long-distance quantum networks for quantum computing, teleportation, and quantum cryptography for secure data transfer. The research also continues to create tremendous interest among scientists and laymen alike. The research is getting exposure in media and at events that target very diverse audiences, including the Annenberg Online class on Manipulating Light, and Chicago's Museum of Science and Industry's new permanent exhibition and associated interactive games that are aimed at kids. The PI and her students dedicate significant amounts of their time to convey their excitement about science and to help educate the public about scientific research.