@article {1174, title = {Photon-Photon Interactions via Rydberg Blockade}, journal = {Physical Review Letters}, volume = {107}, year = {2011}, month = {2011/9/22}, abstract = { We develop the theory of light propagation under the conditions of electromagnetically induced transparency (EIT) in systems involving strongly interacting Rydberg states. Taking into account the quantum nature and the spatial propagation of light, we analyze interactions involving few-photon pulses. We demonstrate that this system can be used for the generation of nonclassical states of light including trains of single photons with an avoided volume between them, for implementing photon-photon quantum gates, as well as for studying many-body phenomena with strongly correlated photons. }, doi = {10.1103/PhysRevLett.107.133602}, url = {http://arxiv.org/abs/1103.3700v1}, author = {Alexey V. Gorshkov and Johannes Otterbach and Michael Fleischhauer and Thomas Pohl and Mikhail D. Lukin} } @article {1170, title = {Photonic Phase Gate via an Exchange of Fermionic Spin Waves in a Spin Chain }, journal = {Physical Review Letters}, volume = {105}, year = {2010}, month = {2010/8/5}, abstract = { We propose a new protocol for implementing the two-qubit photonic phase gate. In our approach, the pi phase is acquired by mapping two single photons into atomic excitations with fermionic character and exchanging their positions. The fermionic excitations are realized as spin waves in a spin chain, while photon storage techniques provide the interface between the photons and the spin waves. Possible imperfections and experimental systems suitable for implementing the gate are discussed. }, doi = {10.1103/PhysRevLett.105.060502}, url = {http://arxiv.org/abs/1001.0968v3}, author = {Alexey V. Gorshkov and Johannes Otterbach and Eugene Demler and Michael Fleischhauer and Mikhail D. Lukin} } @article {1180, title = {Universal Approach to Optimal Photon Storage in Atomic Media}, journal = {Physical Review Letters}, volume = {98}, year = {2007}, month = {2007/3/19}, abstract = { We present a universal physical picture for describing storage and retrieval of photon wave packets in a Lambda-type atomic medium. This physical picture encompasses a variety of different approaches to pulse storage ranging from adiabatic reduction of the photon group velocity and pulse-propagation control via off-resonant Raman fields to photon-echo based techniques. Furthermore, we derive an optimal control strategy for storage and retrieval of a photon wave packet of any given shape. All these approaches, when optimized, yield identical maximum efficiencies, which only depend on the optical depth of the medium. }, doi = {10.1103/PhysRevLett.98.123601}, url = {http://arxiv.org/abs/quant-ph/0604037v3}, author = {Alexey V. Gorshkov and Axel Andre and Michael Fleischhauer and Anders S. Sorensen and Mikhail D. Lukin} }