title: Zero to π Continuously Controllable Cross Phase Modulation in Doppler Broadened N-Type Electromagnetically Induced Transparency Medium.
abstract: We demonstrate an observation of zero to π continuously controllable cross-phase-modulation based on N-type electromagnetically induced transparency scheme in a room-temperature87Rb vapor. We theoretically and experimentally show that the signal field acquires a π phase shift compared with the reference light in the presence of the phase-control field. Using the method of the optical Mach-Zehnder interferometer, we demonstrate that a zero to π continuously controllable phase gate can be built by modulating the phase-control field. In addition, our theoretical calculation agrees well with the experimental observation, and the results presented in this work hold the potential applications for the orthogonal polarization/vector gate in the quantum information processing.
authors.affiliation: National Institute of Standard and Technology, Gaithersburg, Maryland USA 20899; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: R B
authors.initials: RB
authors.lastname: Li
authors.affiliation: National Institute of Standard and Technology, Gaithersburg, Maryland USA 20899; School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: C J
authors.initials: CJ
authors.lastname: Zhu
authors.affiliation: National Institute of Standard and Technology, Gaithersburg, Maryland USA 20899.
authors.forename: L
authors.initials: L
authors.lastname: Deng
authors.affiliation: National Institute of Standard and Technology, Gaithersburg, Maryland USA 20899.
authors.forename: E W
authors.initials: EW
authors.lastname: Hagley