title: Experimental demonstration of spinor slow light.
abstract: Slow light based on the effect of electromagnetically induced transparency is of great interest due to its applications in low-light-level nonlinear optics and quantum information manipulation. The previous experiments all dealt with the single-component slow light. Here, we report the experimental demonstration of two-component or spinor slow light using a double-tripod atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by six light fields. The oscillation due to the interaction between the two components was observed. On the basis of the stored light, our data showed that the double-tripod scheme behaves like the two outcomes of an interferometer enabling precision measurements of frequency detuning. We experimentally demonstrated a possible application of the double-tripod scheme as quantum memory/rotator for the two-colour qubit. Our study also suggests that the spinor slow light is a better method than a widely used scheme in the nonlinear frequency conversion.
authors.affiliation: Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Meng-Jung
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania.
authors.forename: Julius
authors.initials: J
authors.lastname: Ruseckas
authors.affiliation: Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Chin-Yuan
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania.
authors.forename: Viačeslav
authors.initials: V
authors.lastname: Kudriašov
authors.affiliation: Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Kao-Fang
authors.initials: KF
authors.lastname: Chang
authors.affiliation: Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Cho
authors.affiliation: Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania.
authors.forename: Gediminas
authors.initials: G
authors.lastname: Juzeliānas
authors.affiliation: Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Ite A
authors.initials: IA
authors.lastname: Yu