Control of Four-Level Quantum Coherence via Discrete Spectral Shaping of an Optical Frequency Comb

We present an experiment demonstrating high-resolution coherent control of a four-level atomic system in a closed (diamond) type configuration. A femtosecond frequency comb is used to establish phase coherence between a pair of two-photon transitions in cold Rb atoms. By controlling the spectral phase of the frequency comb we demonstrate the optical phase sensitive response of the diamond system. The high-resolution state selectivity of the comb is used to demonstrate the importance of the signs of dipole moment matrix elements in this type of closed-loop excitation. Finally, the pulse shape is optimized resulting in a 256% increase in the two-photon transition rate by forcing constructive interference between the mode pairs detuned from an intermediate resonance.Comment: 5 pages, 4 figures Submitted to Physical Review Letter

Some Evidence of Information Aggregation in Auction Prices

Paper was previously titled "The Informativeness of Prices as Quality Signals in the Thoroughbred Industry"Efficient Markets Hypothesis, information aggregation, auctions, Thoroughbred industry, Agribusiness, Livestock Production/Industries,

Direct frequency comb measurements of absolute optical frequencies and population transfer dynamics

A phase-stabilized femtosecond laser comb is directly used for high-resolution spectroscopy and absolute optical frequency measurements of one- and two-photon transitions in laser-cooled \rb atoms. Absolute atomic transition frequencies, such as the 5S$_{1/2}$ F=2 \ra 7S$_{1/2}$ F"=2 two-photon resonance measured at 788 794 768 921(44) kHz, are determined without \textit{a priori} knowledge about their values. Detailed dynamics of population transfer driven by a sequence of pulses are uncovered and taken into account for the measurement of the 5P states via resonantly enhanced two-photon transitions.Comment: 5 pages, 4 figures, submitte

Metabolic Activity of the Epiphytic Community Associated with Spartina alterniflora

Primary production and respiration rates were determined for two epiphytic communities associated with Spartina alternifloraLoisel., in the southwestern Barataria Bay area of Louisiana. The communities studied were: (1) a shoreline community and (2) a community 1.5 meters inland from the shoreline site. Annual mean net production and respiration rates for the shoreline community were 25.8 and -19.6 mg C • (m2 substrate area)-1 • h-1 respectively;whereas the inland community showed corresponding rates of -3.3 and -12.5 mg C • (m2 substrate area)-1 • h-1, respectively. Thus, the shoreline community was a net contributor to system production; the inland community was an energy sink. The inland community was elevated 15 to 20 cm above the shoreline community, lacked the conspicuous filamentous algal growth common at the shoreline location, and had a significantly smaller diatom population. The role of epiphytes is speculated to be one of quality rather than quantity production

Determinants of Weanling Thoroughbred Auction Prices

Determinants of prices of 1,302 weanling Thoroughbreds sold at the 2010 Keeneland November Breeding Stock Sale are investigated. A hedonic pricing model is adopted to identify price determinants, and the corresponding marginal values of those determinants are estimated. Prices were responsive to pedigree quality variables, including the sire\u27s stud fee, the stage of the sire\u27s breeding career, and whether the dam or the dam\u27s progeny had earned “black type.” In addition, individual weanling characteristics such as gender, age, state of birth, and sale placement influenced price. Results can be used as a decision tool by both buyers and sellers

Metabolic Activity of the Epiphytic Community Associated with Spartina alterniflora

Primary production and respiration rates were determined for two epiphytic communities associated with Spartina alternifloraLoisel., in the southwestern Barataria Bay area of Louisiana. The communities studied were: (1) a shoreline community and (2) a community 1.5 meters inland from the shoreline site. Annual mean net production and respiration rates for the shoreline community were 25.8 and -19.6 mg C • (m2 substrate area)-1 • h-1 respectively;whereas the inland community showed corresponding rates of -3.3 and -12.5 mg C • (m2 substrate area)-1 • h-1, respectively. Thus, the shoreline community was a net contributor to system production; the inland community was an energy sink. The inland community was elevated 15 to 20 cm above the shoreline community, lacked the conspicuous filamentous algal growth common at the shoreline location, and had a significantly smaller diatom population. The role of epiphytes is speculated to be one of quality rather than quantity production

Entanglement of Atomic Qubits using an Optical Frequency Comb

We demonstrate the use of an optical frequency comb to coherently control and entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used to efficiently and coherently transfer population between electronic and vibrational states of trapped atomic ions and implement an entangling quantum logic gate with high fidelity. This technique can be extended to the high field regime where operations can be performed faster than the trap frequency. This general approach can be applied to more complex quantum systems, such as large collections of interacting atoms or molecules.Comment: 4 pages, 5 figure

High resolution atomic coherent control via spectral phase manipulation of an optical frequency comb

Sem informaçãoWe demonstrate high resolution coherent control of cold atomic rubidium utilizing spectral phase manipulation of a femtosecond optical frequency comb. Transient coherent accumulation is directly manifested by the enhancement of signal amplitude and spectral resolution via the pulse number. The combination of frequency comb technology and spectral phase manipulation enables coherent control techniques to enter a new regime with natural linewidth resolution. © 2006 The American Physical Society.We demonstrate high resolution coherent control of cold atomic rubidium utilizing spectral phase manipulation of a femtosecond optical frequency comb. Transient coherent accumulation is directly manifested by the enhancement of signal amplitude and spectral resolution via the pulse number. The combination of frequency comb technology and spectral phase manipulation enables coherent control techniques to enter a new regime with natural linewidth resolution.We demonstrate high resolution coherent control of cold atomic rubidium utilizing spectral phase manipulation of a femtosecond optical frequency comb. Transient coherent accumulation is directly manifested by the enhancement of signal amplitude and spectral resolution via the pulse number. The combination of frequency comb technology and spectral phase manipulation enables coherent control techniques to enter a new regime with natural linewidth resolution.961514Sem informaçãoSem informaçãoSem informaçãoUdem, Th., Holzwarth, R., Hänsch, T.W., (2002) Nature (London), 416, p. 233. , NATUAS. 0028-0836. 10.1038/416233aCundiff, S.T., Ye, J., (2003) Rev. Mod. Phys., 75, p. 325. , RMPHAT 0034-6861 10.1103/RevModPhys.75.325Marian, A., (2004) Science, 306, p. 2063. , SCIEAS 0036-8075 10.1126/science.1105660Marian, A., (2005) Phys. Rev. Lett., 95, p. 023001. , PRLTAO 0031-9007 10.1103/PhysRevLett.95.023001Diddams, S.A., (2001) Science, 293, p. 825. , SCIEAS 0036-8075 10.1126/science.1061171Ye, J., Ma, L.-S., Hall, J.L., (2001) Phys. Rev. Lett., 87, p. 270801. , PRLTAO 0031-9007 10.1103/PhysRevLett.87.270801Holman, K.W., (2005) Opt. Lett., 30, p. 1225. , OPLEDP 0146-9592 10.1364/OL.30.001225Jones, R.J., (2005) Phys. Rev. Lett., 94, p. 193201. , PRLTAO 0031-9007 10.1103/PhysRevLett.94.193201Gohle, C., (2005) Nature (London), 436, p. 234. , NATUAS 0028-0836 10.1038/nature03851Kuklinski, J.R., (1989) Phys. Rev. A, 40, p. 6741. , PLRAAN 1050-2947 10.1103/PhysRevA.40.6741Broers, B., Van Linden Van Den Heuvell, H.B., Noordam, L.D., (1992) Phys. Rev. Lett., 69, p. 2062. , PRLTAO 0031-9007 10.1103/PhysRevLett.69.2062Meshulach, D., Silberberg, Y., (1998) Nature (London), 396, p. 239. , NATUAS 0028-0836 10.1038/24329Balling, P., Maas, D.J., Noordam, L.D., (1994) Phys. Rev. A, 50, p. 4276. , PLRAAN 1050-2947 10.1103/PhysRevA.50.4276Chatel, B., (2003) Phys. Rev. A, 68, p. 041402. , PLRAAN 1050-2947 10.1103/PhysRevA.68.041402Oron, D., (2002) Phys. Rev. Lett., 88, p. 063004. , PRLTAO 0031-9007 10.1103/PhysRevLett.88.063004Salzmann, W., (2006) Phys. Rev. A, 73, p. 023414. , PLRAAN 1050-2947 10.1103/PhysRevA.73.023414Felinto, D., Acioli, L.H., Vianna, S.S., (2004) Phys. Rev. A, 70, p. 043403. , PLRAAN 1050-2947 10.1103/PhysRevA.70.043403Martinez, O.E., (1987) IEEE J. Quantum Electron., 23, p. 59. , IEJQA7 0018-9197 10.1109/JQE.1987.1073201Yoon, T.H., (2001) Phys. Rev. A, 63, p. 011402. , PLRAAN 1050-2947 10.1103/PhysRevA.63.011402Vala, J., (2001) Phys. Rev. A, 63, p. 013412. , PLRAAN 1050-2947 10.1103/PhysRevA.63.013412We thank funding support from ONR, NSF, and NIST