Bulletin of the American Physical Society
2005 36th Meeting of the Division of Atomic, Molecular and Optical Physics
Tuesday–Saturday, May 17–21, 2005; Lincoln, Nebraska
Session P1: Hot Topics |
Hide Abstracts |
Chair: Kate Kirby, ITAMP, Harvard-Smithsonian Center for Astrophysics Room: Burnham Yates Conference Center Ballroom I |
Saturday, May 21, 2005 9:00AM - 9:36AM |
P1.00001: Generation of attosecond XUV supercontinuum by a polarization gating Invited Speaker: Since high-order harmonic generation is sensitive to the ellipticity of the laser field, it was proposed that single attosecond pulses could be produced by gating the harmonic generation process using laser pulses with a time-dependent ellipticity. We have created such laser fields with \textit{few-cycle} circular pulses. By using few-cycle laser pulses, it avoids significant ionization of the atom by the leading edge of the pulse. The laser beam from the Kansas Light Source was focused into a hollow-core fiber filled with argon gas to generate the few-cycle pulses. The pulse exiting the fiber passed through two pairs of chirp mirrors and was negatively chirped with a center wavelength at 750 nm. This chirp was compensated by a fused silica plate so that the pulse duration became tunable by adjusting the plate thickness. The shortest laser pulses are 6.2 fs. The pulse with a time-dependent ellipticity was then produced with a delay induced by a quartz plate. Finally, the pulse was focused by a parabolic mirror into a gas jet. The generated high harmonic signal was dispersed by a transmission grating and recorded by a microchannel plate detector and a CCD camera. A 30 eV to 100 eV supercontinuum has been obtained with the polarization gating. This continuum indicates the generation of a single attosecond pulse. Numerical simulations done with a nonadiabatic Lewenstein model combined with three-dimensional propagation confirms that the supercontinuum corresponds to a chirped single attosecond pulse. The pulse is less than 100 attoseconds when the chirp is compensated. We will show that the carrier-envelope phase of the laser pulse can significantly affect the attosecond supercontinuum generation. [Preview Abstract] |
Saturday, May 21, 2005 9:36AM - 10:12AM |
P1.00002: Connecting the Raman and EIT physics for a 88Sr high-accuracy optical clock Invited Speaker: Atomic systems based on a three-level $\Lambda $ configuration offer interesting spectroscopic properties associated to the production of a coherence between the two lower states. Under laser excitation by two lasers, dressed and probe, the Raman peak and the electromagnetically induced transparency dip appear when the difference between the laser frequencies matches the energy separation between the lower states of the $\Lambda $ system. That difference stabilized to an atomic splitting can be used as an optical clock. An application to $^{88}$Sr atoms in an optical lattice was proposed in (1). The coherent coupling between the 5s$^{2}$ $^{1}$S$_{0}$ ground state and the first excited state, 5s5p $^{3}$P$_{0}$ is mediated by the broad second excited 5s5p $^{1}$P$_{1}$ state, exploiting the electromagnetically induced transparency. The effective linewidth of the clock transition can be chosen at will by adjusting the intensity of the dressed laser. (1) R. Santra, E. Arimondo,T. Ido, C. H. Greene, and Jun Ye, arXiv:physics/0411197 (2004). [Preview Abstract] |
Saturday, May 21, 2005 10:12AM - 10:48AM |
P1.00003: Circuit Quantum Electrodynamics: Doing Quantum Optics on a Chip Invited Speaker: I will describe experiments in which the strong coupling limit of cavity quantum electrodynamics has been realized for the first time using superconducting circuits. In our approach, we use a Cooper-pair box as an artificial atom, which is coupled to a one-dimensional cavity formed by a transmission line resonator. When the Cooper-pair box qubit is detuned from the cavity resonance frequency, we perform high-fidelity dispersive quantum non-demolition read-out of the qubit state. Using this read-out technique, we have characterized the qubit properties spectroscopically, performed Rabi and Ramsey experiments with the qubit, and attained coherence times greater than 500 ns and a visibility greater than 90 percent, indicating that this architecture is extremely attractive for quantum computing and control. In the case when the qubit is tuned into resonance with the cavity, we observe the vacuum Rabi splitting of the cavity mode, indicating that the strong coupling regime is attained, and coherent superpositions between the qubit and a single photon are generated. [Preview Abstract] |
Saturday, May 21, 2005 10:48AM - 11:24AM |
P1.00004: Extreme Nonlinear Optics: Applied Attosecond Science Invited Speaker: High-order harmonic generation (HHG) provides a useful source of coherent, ultrafast light in the extreme ultraviolet (EUV) region of the spectrum, with applications in ultrafast atomic and molecular dynamics, coherent control of electron dynamics, lithography, high-resolution imaging, site-specific spectroscopy and bio-microscopy. In HHG, an intense laser pulse is focused into a medium. The highly nonlinear interaction between the laser light and the atoms creates higher-order harmonics that emerge from the medium as a coherent, low-divergence, beam. In general, to generate the brightest harmonics from a medium, the conversion process must be phase matched, even in the presence of significant levels of ionization that introduce a large plasma-induced dispersion and prevent the laser and the harmonic light from propagating at the same phase velocity. A short pulse is also needed, since this reduces the ionization level at a particular laser intensity and harmonic photon energy. And finally, an atom with large effective susceptibility is needed to generate the brightest harmonics. In this talk, we show that by combining phase matching, quasi phase matching (QPM), and pulse compression in a single gas-filled waveguide, we can shift the phase-matching region in large atoms to significantly higher energies. We also show that use of a temporally-sharp laser pulse generates an x-ray continuum at low pressure, which may correspond to an isolated, 50 attosecond, pulse. Finally, the role of carrier-envelope phase stabilization of the driving laser pulses on the output harmonics from the medium will also be discussed. Applications of high harmonics in ultrafast surface and photoacoustic spectroscopies will also be presented. N. Wagner et al., ``High-Order Harmonic Generation up to 250 eV from Highly Ionized Argon,'' Phys. Rev. Lett. 93, 173902 (2004). A. Paul et al., ``Quasi-phase-matched generation of coherent extreme-ultraviolet light,'' Nature 421, 51 (2003). E.A.Gibson et al., ``Coherent soft x-ray generation in the water window with quasi- phase matching'', Science 302, 95 (2003). I.P. Christov et al., ``Attosecond Pulse Generation in the Single Cycle Regime,'' Phys. Rev. Lett. 78, 1251 (1997). [Preview Abstract] |
Saturday, May 21, 2005 11:24AM - 12:00PM |
P1.00005: Observation of the Vacuum-Rabi Spectrum for One Trapped Atom Invited Speaker: \begin{document} A cornerstone of optical physics is the interaction of a single atom with the electromagnetic field of a high quality resonator. Of particular importance is the regime of strong coupling, for which the frequency scale $g $ associated with reversible evolution for the atom-cavity system exceeds the rates $(\gamma ,\kappa )$ for irreversible decay of atom and cavity field, respectively. In the domain of strong coupling, a photon emitted by the atom into the cavity mode is likely to be repeatedly absorbed and re-emitted at the single-quantum Rabi frequency $2g$ before being irreversibly lost into the environment. This oscillatory exchange of excitation between atom and cavity field results from a normal-mode splitting in the eigenvalue spectrum of the atom-cavity system, and has been dubbed the vacuum-Rabi splitting. Without exception experiments related to the vacuum-Rabi splitting in cavity QED with single atoms have required averaging over trials with many atoms ($% \gtrsim 10^{3}$) to obtain quantitative spectral information. By contrast, the implementation of complex algorithms in quantum information science requires the capability for repeated manipulation of an individual quantum system. With this goal in mind, we have succeeded in recording the entire vacuum-Rabi spectrum for one-and-the-same atom strongly coupled to the field of a high-finesse optical resonator [1]. These measurements are made possible by a new Raman scheme for cooling atomic motion along the cavity axis for single atoms trapped within a state-insensitive intracavity FORT [2], with inferred atomic localization $\Delta z_{axial}\simeq 33~\mathrm{nm}$. Our measurements represent an important milestone towards the realization of more complex tasks in quantum computation and communication [3]. \begin{thebibliography}{9} \bibitem{boca04} A. Boca, R. Miller, K. M. Birnbaum, A. D. Boozer, J. McKeever, and H. J. Kimble, Phys. Rev. Lett. \textbf{93}, 233603 (2004). \bibitem{mckeever03} J. McKeever, J.R. Buck, A.D. Boozer, A. Kuzmich, H.-C.Nagerl, D.M. Stamper-Kurn, H.J. Kimble, Phys. Rev. Lett. \textbf{90}, 133602 (2003). \bibitem{ack} This work was carried out in collaboration with A. Boca, R. Miller, K.~M. Birnbaum, A.~D. Boozer, and J. McKeever, and was supported by the Caltech MURI Center for Quantum Networks, by the National Science Foundation, and by the Advanced Research and Development Activity (ARDA). \end{thebibliography} \end{document} [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700