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Scholarly Interest Report
         
F. Barry Dunning
Professor
Sam and Helen Worden Professor of Physics
 
e-mail:bdunning@rice.edu
 
  • B.Sc. (Special) First Class Honors, (1966) University College London, London, England
  • Ph.D., (1969) University College London, London, England
 
Primary Department
   Department of Physics and Astronomy
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Department Affiliations
 
  • Department of Physics and Astronomy
  •  
     
    Research Areas
     Experimental Atomic, Molecular, and Optical Physics, Nonlinear Dynamics, Chemical Physics.
     

    Research Statement

     

     


    My research focuses on atoms in which one electron is excited to a state of very large principal quantum number n, termed Rydberg atoms.  Such atoms possess properties quite unlike those normally associated with atoms in ground or low-lying excited states.  For example, because the size of an atom scales as n2, they are physically very large.  An atom with n~400 has a diameter approaching 20 μ-m.  Their classical electron orbital periods are also very long, ~10 ns at n~400, and this we exploit to control and manipulate their electronic wave functions using pulsed electric fields whose characteristic times (duration, rise/fall times) are less than this period.  Application of such pulses leads to the formation of wave packets that comprise a coherent superposition of adjacent Rydberg states. These wave packets display novel dynamical behavior that can mimic the classical motion of an excited electron, thereby providing a bridge between quantum and classical physics. Our studies show that, with careful choice of the amplitude and width of the pulses (or application of several pulses), it is possible to control and manipulate atomic wavefunctions with remarkable precision.  The goal is to use carefully-tailored sequences of pulses to engineer atomic wavefunctions and produce “designer” atoms to study classical-quantum correspondence, to use periodic trains of pulses to create non-dispersive wave packets and to probe non-linear dynamics and classical/quantum chaos, to study atom/field interactions in the ultra-fast ultra-intense regime, to explore information storage/retrieval in atoms, and to study the behavior of strongly-coupled Rydberg/Rydberg systems.  Initial work centered on potassium Rydberg atoms contained in a tightly-collimated atomic beam but has now been extended to include strontium Rydberg atoms contained in both an atomic beam and in an ultra-cold atomic gas or Bose-Einstein condensate (BEC).


     


    The starting point for many of our studies is the production of strongly-polarized quasi-one-dimensional (quasi-1D) high-n Rydberg atoms by photo-exciting extreme red-shifted Stark states in the presence of a weak dc field.  Protocols have been developed using pulsed electric fields to characterize such states and monitor their time evolution.  Techniques have also been devised to convert such states into quasi-two-dimensional (quasi-2D) “circular” states in which the electron orbits in a plane, and probe their evolution.  The opportunities afforded by the creation of quasi-1D and -2D atoms are being explored.  These include the use of periodic drive fields to create localized non-dispersive wave packets that mimic the behavior of a classical electron and to transport these wave packets to states of higher n.  Measurements with strontium Rydberg atoms show that, even at high n, the regime where dipole blockade becomes important can be accessed opening up new opportunities to study strongly-coupled Rydberg atom pairs and their possible manipulation to form long-lived “molecular” species through periodic driving.  The production of long-lived “planetary atom” states in strontium that contain two excited electrons is also being examined.  The evolution of cold Rydberg gases into a strongly-coupled ultracold neutral plasma through collisions is also under investigation.  Studies of the control of the interactions between atoms in a strontium BEC by dressing the ground-state atoms with an admixture of a higher-lying Rydberg state using lasers have been initiated with the long-range goal of realizing soliton formation in three dimensions and creation of a supersolid


     


    Because the Rydberg electron is typically far from its associated core ion it will, in collisions with neutral targets, behave as an independent particle allowing a Rydberg atom to be viewed as an ultra-low-energy electron trap.  Potassium Rydberg atoms are therefore being used to examine electron attachment to molecules.  The creation of novel negative ion species in such collisions is observed including the formation of negative ions in which the electron is weakly bound by the electric dipole moment of the parent molecule.  The creation of heavy-Rydberg ion-pair states comprising a positive-negative ion pair that orbit at large radius weakly bound by their mutual electrostatic attraction is also seen.  The physical and chemical properties of such species are being examined using a newly-commissioned apparatus.


     


    Each of the above experimental programs makes use of advanced experimental techniques including ultrahigh vacuum technology, state-of-the-art dye and diode laser systems, high-speed analog and digital electronics, and computer-based data acquisition and control systems.  The work relies heavily on the efforts of several graduate students:


     


    Changhao Wang


    Michael Kelley


    Xinyue Zhang


    Sitti Buathong


    Roger Ding


    Gavin Fields



     

     

    Research Topics

     

     Protocols to create localized wave packets in very-high-n (n ~ 300) states that travel in near circular orbits about the nucleus are being developed.  These wave packets represent the closest analog yet achieved to the original Bohr model of the hydrogen atom, i.e., an electron in circular classical orbit about the nucleus.  Initially, quasi-one-dimensional Rydberg atoms strongly polarized along the x axis are created by photoexciting the lowest-lying states in the n ~ 306 Stark manifold in the presence of a weak dc field, directed along the x axis.  This is then turned off adiabatically and a strong transverse field is suddenly applied along the y axis.  This leads to the creation of a Stark wave packet which undergoes periodic changes in its y component of angular momentum.  Turn-off of the transverse field at an appropriate time leaves a localized wave packet traveling in a near-circular orbit (n ~ l ~ m) that undergoes transient localization forming a Bohr-like state that remains localized for several orbits before dephasing and collapsing to a quasi-stationary near-circular state.  The use of radio frequency fields to maintain strongly localized Bohr-like wave packets for many hundreds of orbits is being explored.  With careful choice of the period, amplitude, and phase of the drive field wave packets have been generated, termed Trojan wave packets that execute near-circular motion and that remain localized indefinitely and whose motion mimics that of Jupiter's Trojan asteroids.  Furthermore, the locking to the drive field is so strong that by slowly varying the drive frequency the wave packet can be transported to states of much higher n, furnishing a new technique for the control of atomic wavefunctions.  This work is being extended using strontium to explore the creation of quasi-stable planetary atoms containing two excited electrons.


     


    Schemes for the production of quasi-1D high-n Rydberg atoms at densities in the blockade regime where the excitation of one atom inhibits the subsequent excitation of its neighbors are being explored as this allows the controlled production of Rydberg atoms with well-defined initial separations.  At n~300, creation of a quasi-1D atom, for an effective laser linewidth of ~5 MHz, suppress excitation of a second similar atom within a radius of ~100 μ-m extending strong many-body interactions well into the mesoscopic regime.  Measurements using two- and three-photon excitation of strontium atoms in a beam show that it is possible to achieve the required densities.  Access to the dipole blockade regime will enable detailed studies of the interactions between strongly-coupled Rydberg atoms and their dependence on the coupling strength, which can be varied by changing n or by using the techniques we have already developed to manipulate the atomic state.  Questions of interest focus on the dynamics of energy interchange and their dependence on the degree of coupling.  Excitation to Rydberg states whose size is comparable to the interatomic spacing will lead to the formation of a transient Rydberg “molecule” whose stability against autoionization is governed by electron-electron scattering.  Of particular interest are long-lived configurations where, due to their correlated motions, the electrons remain far apart.  Such states might also, through periodic driving with an electric field lead to formation of a correlated phase-locked Rydberg pair wave packet.


     In other experiments strong tunable long-range interactions are being created in cold atom samples and BECs by dressing ground state strontium atoms contained in an optical dipole trapwith an admixture of an excited Rydberg levelusing laser radiation tuned near resonance with the transition to the Rydberg state.  Strontium possesses narrow intercombination lines which can be used to obtain significantly longer sample lifetimes and decoherence times as compared to the use of alkali atoms.  These ongoing experiments will advance our understanding of quantum materials and emergent phenomena and lead to new technological advances. Initial measurements, however, have revealed that even weak Rydberg dressing can lead to surprisingly large ground state atom loss rates from the trap.  The processes responsible continue to be examined but are attributed to the excitation of Rydberg atoms which can result in direct trap loss through recoil and in the population of very-long-lived metastable states.  Measurements of the time dependence of the trap loss suggest a mechanism in which the creation of a small number of “seed” Rydberg atoms triggers “avalanche-like” growth in the numbers of Rydberg atoms excited.  This work shows that, if effects due to Rydberg dressing are to be observed, small samples and/or short time scales may be essential.  To this end, the use of Autler-Townes spectroscopy has been exploited to study the effects of interactions induced by Rydberg dressing on timescales of a few microseconds.  The effects of interactions are observed in shifts, asymmetries, and broadening of the measured atom loss spectra.  The experiment is analyzed using a density matrix approach that accounts for interaction-induced level shifts and dephasing and incorporates the effects of Rydberg blockade.  The model provides good agreement with experiment for short dressing times but for longer dressing times breaks down, suggesting that additional sources of dephasing become important which continue to be investigated.


     


    Spectroscopic measurements of trap loss also revealed the production of very-long-range weakly-bound Rydberg molecules in which scattering of the excited Rydberg atom from a neighboring ground state atom can bind the two atoms together.  Detailed studies of such molecules are underway as they represent a new type of chemical bond and can display surprising features such as the presence of large permanent electric dipole moments, even in the case of a homonuclear molecule.  Measurements reveal the production of Rydberg molecules in both ground and excited vibrational states whose energies are in excellent agreement with those predicted theoretically.  The data also show the presence of features that result from the creation of trimer (tetramer) states that comprise a parent Rydberg atom and two (three) bound atoms and whose energies are given approximately by the separate binding energies of the atoms.  Measurements on these novel species are continuing to compare their properties (lifetimes, electric field ionization characteristics, etc.) to those of the parent Rydberg atoms.


    Collisions between high-n Rydberg atoms and molecular targets are being used to examine electron attachment to molecules.  The creation of novel negative ion species is observed including the formation of ions in which the electron is weakly bound by the electric dipole moment of the parent molecule.  Such ions display many of the characteristics associated with Rydberg atoms which is, perhaps, not unexpected as they both contain a weakly-bound electron in a diffuse orbital.  Rydberg atom collisions can also lead to creation of so-called heavy-Rydberg ion-pair states comprising a positive-negative ion pair that orbit at large radius weakly bound by their mutual Coulomb attraction.  The lifetimes and decay modes of such species are being examined.  Ion-pair states involving molecular negative ions can decay through mutual charge transfer or the conversion of internal energy in the negative ion into translational energy of the ion pair.  Those states involving atomic negative ions have very long lifetimes, allowing studies of their chemical and collisional properties.


     


    Each of the above experimental programs makes use of advanced experimental techniques including ultrahigh vacuum technology, state-of-the-art dye, diode and fiber laser systems, high-speed analog and digital electronics, and computer-based data acquisition and control systems.  The work relies heavily on the efforts of several graduate students:




    Changhao Wang


    Michael Kelley


    Xinyue Zhang


    Sitti Buathong


    Roger Ding


    Gavin Fields



     

     
    Teaching Areas
     Freshman physics
    Sophomore physics
     
    Selected Publications
     Refereed articles
     

    B. J. DeSalvo, J. A. Aman, F. B Dunning, T. C. Killian, H. R. Sadeghpour, S. Yoshida, and J. Burgdörfer "Ultralong-range Rydberg molecules in a divalent atomic system." Physical Review A, 92 (2015) : 031403(R).

     
     

    M. Kelley, S. Buathong, and F. B. Dunning "Use of heavy-Rydberg ion-pair states to probe dissociative electron attachment." Journal of Physics: Conference Series, 635 (2015) : 012024.

     
     

    S. Buathong, M. Kelley, C. H. Wang, and F. B. Dunning "Probing dissociative electron attachment through formation of heavy-Rydberg ion pair states in Rydberg atom collisions." Chemical Physics Letters, 618 (2015) : 153.

     
     

    X. Zhang, F. B. Dunning, S. Yoshida, and J. Burgdörfer "Rydberg blockade effects at n~300 in strontium." Physical Review A, 92 (2015) : 051402(R).

     
     

    C. H. Wang, M. Kelley, S. Buathong, and F. B. Dunning "Dynamics of heavy-Rydberg ion-pair formation in K(14p,20p)-SF6, CCl4 collisions." Journal of Chemical Physics, 140 (2014) : 234306.

     
     

    M. Hiller, S. Yoshida, J. Burgdörfer, S. Ye, X. Zhang, and F. B. Dunning "Characterizing high-n, quasi-one-dimensional strontium Rydberg atoms." Physical Review A, 89 (2014) : 023426.

     
     

    S. Buathong, M. Kelley, C. H. Wang, and F. B. Dunning "Probing dissociative electron attachment through formation of heavy-Rydberg ion pair states in Rydberg atom collisions." Chemical Physics LettersIn Press

     
     

    S. Ye, X. Zhang, F. B. Dunning, S. Yoshida, M. Hiller, and J. Burgdörfer "Efficient three-photon excitation of quasi-one-dimensional strontium Rydberg atoms with n~300." Physical Review A, 90 (2014) : 013401.

     
     

    Korana Burke, Kevin A. Mitchell, Shuzhen Ye, and F. Barry Dunning "Chaotic ionization of a stationary electron state via a phase space turnstile." Phys. Rev. A, 88 (2013) : 01308.

     
     

    P. McQuillen, X. Zhang, T. Strickler, F. B. Dunning, and T. C. Killian "Imaging the evolution of an ultracold strontium Rydberg gas." Phys. Rev. A, 87 (2013) : 013407.

     
     

    S. Ye, X. Zhang, T.C. Killian, F.B.Dunning, M. Hiller, S. Yoshida, S. Nagele, and J. Burgdorfer "Production of very-high-n strontium Rydberg atoms." Phys. Rev. A, 88 (2013) : 043430.

     
     

    Y. Pu and F. B. Dunning "Ionization of Rydberg atoms at patterned electrode arrays." Phys. Rev. A, 88 (2013) : 012901.

     
     

    B. Wyker, S. Ye, F. B. Dunning, S. Yoshida, C. O. Reinhold, and J. Burgdörfer "Creating and transporting Trojan wave packets." Phys. Rev. Lett., 108 (2012) : 043001.

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdörfer, B. Wyker, S. Ye, and F. B. Dunning "Analysis of circular wave packets generated by pulsed electric fields." Nucl. Inst. Meth. Phys. Res. B, 279 (2012) : 4-7.

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdörfer, S. Ye, and F. B. Dunning "Photoexcitation of n~305 Rydberg atoms in the presence of an rf drive field." Phys. Rev. A, 86 (2012) : 043415.

     
     

    B. Wyker, S. Ye, F. B. Dunning, S. Yoshida, C. O. Reinhold and J. Burgdörfer "Probing the spatial distribution of high angular momentum Rydberg wave packets." Phys. Rev. A, 84 (2011) : 043412.

     
     

    B. Wyker, S. Ye, T. J. McKinney, F. B. Dunning, C. O. Reinhold, S. Yoshida, and J. Burgdörfer "Decoherence of high-l Rydberg wave packets." J. Phys. B: At. Mol. Opt. Phys., 44 (2011) : 184002.

     
     

    C. O. Reinhold. S. Yoshida, and F, B, Dunning "Electric-field-induced dissociation of heavy Rydberg ion-pair states." J. Chem. Phys., 134 (2011) : 174305.

     
     

    C. O. Reinhold. S. Yoshida, and F, B, Dunning "Electric-field-induced dissociation of heavy Rydberg ion-pair states." J. Chem. Phys., 134 (2011) : 174305.

     
     

    D. D. Neufeld, Y. Pu, and F. B. Dunning "Probing stray surface electric patch fields using Rydberg atoms." Nucl. Instr. and Meth. B, 269 (2011) : 1288.

     
     

    K. Burke, K. A. Mitchell, B. Wyker, S. Ye, and F. B. Dunning "Demonstration of turnstiles as a chaotic ionization mechanism in Rydberg atoms." Phys. Rev. Lett., 107 (2011) : 113002.

     
     

    F. B. Dunning, C. O. Reinhold, S. Yoshida, and J. Burgdörfer "Steering quantum states towards classical Bohr-like orbits." Am. J. Phys., 78 (2010) : 796.

     
     

    M. Cannon, C. H. Wang, F. B. Dunning, and C. O. Reinhold "Lifetimes of heavy-Rydberg ion-pair states formed through Rydberg electron transfer." , 133 (2010) : 064301.

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdörfer, B. Wyker, and F. B. Dunning "Encoding and decoding information in high-n circular wave packets." Phys. Rev. A, 81 (2010) : 063428.

     
     

    Y. Pu, D. D. Neufeld, and F. B. Dunning "Ionization of Rydberg atoms at metallic surfaces." Phys. Rev. A, 81 (2010) : 042904.

     
     

    C. O. Reinhold, S. Yoshida, J. Burgdörfer, B. Wyker, J. J. Mestayer, and F. B. Dunning "Large scale quantum coherence of nearly circular wave packets." J. Phys. B:At. Mol. Opt. Phys., 42, 091003 (2009)

     
     

    F. B. Dunning, J. J. Mestayer, C. O. Reinhold, S. Yoshida, and J. Burgdörfer "Engineering atomic Rydberg states with pulsed electric fields." J. Phys. B: At. Mol. Opt. Phys., 42, 022001 (2009)

     
     

    J. J. Mestayer, B. Wyker, F. B. Dunning, S. Yoshida, C. O. Reinhold, and J. Burgdörfer "Creation of non-dispersive Bohr-like wavepackets." Phys. Rev. A, 79, 033417 (2009)

     
     

    M. Cannon and F. B. Dunning "Formation of heavy Rydberg ion-pair states in collisions of K(np) Rydberg atoms." J. Chem. Phys., 130, 044304 (2009)

     
     

    M. Cannon, C. H. Wang, Y. Liu, F. B. Dunning, and J. D. Steill "Temperature dependence of reactions involving electron transfer in K(np)/C2Cl4 collisions." J. Chem. Phys., 130, 244311 (2009)

     
     

    M. Cannon, C. H. Wang, and F. B. Dunning "Direct observation of K+..Cl- heavy Rydberg ion-pair states formed in K(np)/CCl4 collisions." Chem. Phys. Lett., 479, 30 (2009)

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdörfer, and F. B. Dunning "Comment on "Nondispersing Bohr wave packets"." Phys. Rev. Lett., 103, 149301 (2009)

     
     

    C. O. Reinhold, S. Yoshida, J. Burgdorfer, J. J. Mestayer, B. Wyker, J. C. Lancaster and F. B. Dunning "Tailoring very-high-n circular wave packets" Phys. Rev. A 78, 063413 (2008)

     
     

    D. D. Neufeld, H. R. Dunham, S. Wethekam, J. C. Lancaster, and F. B. Dunning "Ionization of xenon Rydberg atoms at Au(111) surfaces:  Effect of stray fields" Phys. Rev. B 78, 115423 (2008)

     
     

    D. D. Neufeld, H. R. Dunham, S. Wethekam, J. C. Lancaster, and F. B. Dunning "Ionization of xenon Rydberg atoms at oxidized Si(100) surfaces" Surf. Sci. 602, 1306 (2008)

     
     

    J. J. Mestayer, B. Wyker, F. B. Dunning, C. O. Reinhold, S. Yoshida and J. Burgdorfer "Generation of quasi-classical Bohr-like wavepackets using HCPs" Phys. Rev. A 78, 045401 (2008)

     
     

    J. J. Mestayer, B. Wyker, J. C. Lancaster, F. B. Dunning, C. O. Reinhold, S. Yoshida and J. Burgdorfer "Realization of localized Bohr-like wave packets" Phys. Rev. Lett. 100, 243004 (2008)

     
     

    M. Cannon, Y. Liu, L. Suess, and F. B. Dunning "Dipole-bound CH3CN- ions: Temperature dependence of ion production rates and lifetimes" J. Chem. Phys. 128, 244307 (2008)

     
     

    M. Cannon, Y. Liu, and F. B. Dunning "Lifetime of K+-SF6- heavy Rydberg states formed by electron transfer in K(np)-SF6 collisions" Chem. Phys. Lett. 458, 35 (2008)

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdorfer, W. Zhao, J. J. Mestayer, and J. C. Lancaster "Extracting irreversible de-phasing rates from electric dipole echoes in Rydberg Stark wave packets" Phys. Rev A 78, 063414 (2008)

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdorfer. J. J. Mestayer, J. C. Lancaster and F. B. Dunning "Transferring Rydberg wave packets between islands across the chaotic sea" Phys. Rev. A 77, 013411 (2008)

     
     Refereed conference papers
     

    B. J. DeSalvo, J. A. Aman, F. B. Dunning, T. C. Killian, S. Yoshida, and J. Burgdörfer "Trap losses due to near-resonant Rydberg dressing of cold atomic gases." Journal of Physics: Conference Series, 635 (2015) : 092024.

     
     

    B. J. DeSalvo, J. Aman, F. B. Dunning, T. C. Killian, H. R. Sadeghpour, S. Yoshida, and J. Burgdörfer "Production of ultra-long-range Rydberg molecules in a divalent atomic system." Journal of Physics: Conference Series, 635 (2015) : 092023.

     
     

    M. Kelley, S. Buathong, and F. B. Dunning "Use of heavy-Rydberg ion-pair states to probe dissociative electron attachment." Journal of Physics: Conference Series, 635 (2015) : 072002.

     
     

    X. Zhang, F. B. Dunning, S. Yoshida, and J. Burgdörfer "Exploiting Rydberg blockade to probe strongly-coupled Rydberg atom pairs." Journal of Physics: Conference Series, 635 (2015) : 092022.

     
     

    M. Hiller, S. Yoshida, J. Burgdörfer, S. Ye, X. Zhang, and F. B. Dunning "Creation of quasi-one-dimensional high-n strontium Rydberg atoms." Journal of Physics: Conference Series, 488 (2014) : 032002.

     
     

    S. Ye, X. Zhang, T. C. Killian, F. B. Dunning, M. Hiller, S. Yoshida, and J. Burgdörfer "Production of high-n strontium Rydberg atoms." Journal of Physics: Conference Series, 488 (2014) : 022003.

     
     

    B. Wyker, S. Ye, F. B. Dunning, S. Yoshida, C. O. Reinhold, and J. Burgdörfer "Probing and manipulating high-n near-circular Rydberg wave packets." Journal of Physics: Conf. Series, 388 (2012) : 032001.

     
     

    B. Wyker, S. Ye, F. B. Dunning, S. Yoshida, C. O. Reinhold, and J. Burgdörfer "Transporting near-circular Bohr-like wave packets using chirped sine waves." Journal of Physics: Conf Series, 388 (2012) : 032001.

     
     

    C. O. Reinhold, S. Yoshida, and F. B. Dunning "Field-induced dissociation of Rydberg ion-pair states." Journal of Physics: Conf. Series, 388 (2012) : 022064.

     
     

    S. Yoshida, C. O. Reinhold, J. Burgdörfer, B. Wyker, S. Ye, and F. B. Dunning "Decoherence of high-n, high-l Rydberg wave packets by electrical noise and collisions." Journal of Physics: Conf. Series, 388 (2012) : 032003.

     
    Presentations
     Invited Papers
     

    "Production of heavy-Rydberg ion-pair states through Rydberg electron transfer." ITAMP Heavy Rydberg Physics Workshop, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA. (May 2012)

     
     

    "Atomic engineering: Creation of localized very-high-n "Bohr-like" wavepackets." Engineering Rydberg Interactions in Atoms, Molecules and Plasmas: a Collaborative Workshop, Institute for Theoretical Atomic, Molecular and Optical Physics, Harvard. (September, 2009)

     
     

    "Generation of localized "Bohr-like" wavepackets in near-circular orbit about the nucleus." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, University of Virginia, Charlottesville, Virginia. (May, 2009)

     
     

    "Designer atoms: Engineering Rydberg atoms using pulsed electric fields." Workshop on Rydberg Excited atoms/Lundbeck Foundation, Sandbjerg, Denmark. (May 2008)

     
     Invited Talks
     

    speaker.  "Strontium Rydberg atoms: A new tool for probing interacting systems." University of Durham, Durham, England. (June 2015)

     
     

    Research director.  "Use of heavy-Rydberg ion-pair states to probe dissociative electron attachment." International Conference on Photonic, Electronic and Atomic Collisions, Toledo, Spain. (July 2015) With M. Kelley, and S. Buathong

     
     

    Presenter.  "Engineering high-n wavepackets." Winter Graduate School on Atomic, Molecular and Optical Physics, Inst. for Theor. At. Mol. and Opt. Phys., Biosphere 2 Conference Center, Tucson, Arizona. (Jan 4-12 2014) With B. Wyker, J. J.Mestayer, S. Ye, X. Zhang

     
     

    Presenter.  "Engineering near-circular high-n wavepackets." Winter Graduate School on Atomic, Molecular and Optical Physics, Inst. for Theor. At. Mol. and Opt. Phys., Biosphere 2 Conference Center, Tucson, Arizona. (Jan 4-12, 2014) With B. Wyker, J. J. Mestayer, S. Ye., X. Zhang

     
     

    Presenter.  "Experiments with strontium Rydberg atoms." Second International Workshop on Ultracold Rydberg Physics/Univ. de Sao Paulo, Brazil, Recife, Brazil. (Oct 5-8, 2014)

     
     

    Presenter.  "Experiments with strontium Rydberg atoms." Winter Graduate School on Atomic, Molecular and Optical Physics, Inst. for Theor. At. Mol. and Opt. Phys., Biosphere 2 Conference Center, Tucson, Arizona. (Jan 4-12 2014) With S. Ye, X. Zhang, J. Aman, F. Camargo, B. DeSalvo, R. Ding, P. McQuillen, T. Strickler, T. C. Killian

     
     

    "Probing stray electric fields at surfaces with Rydberg atoms." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013)

     
     

    "Probing stray electric fields at surfaces with Rydberg atoms." Conference on Inelastic Ion-Surface Collisions - IISC18, Gatlinburg, TN. (September 2010) With D. D. Neufeld

     
     

    Studies with near-circular high-n wavepackets -Cold Rydberg Gases and Ultracold Plasmas - MPIPKS-ITAMP Tandem Workshop, Dresden

     
     Other
     

    "Extracting irreversible dephasing rates from the echoes of Rydberg Stark wavepackets." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, State College, Pennsylvania. (May 27-31, 2008) With J. J. Mestayer, B. Wyker, C. O. Reinhold, S. Yoshida and J. Burgdörfer

     
     

    "Formation of heavy Rydberg K+-SF6- ion-pair states in K(np)-SF6 collisions." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, State College, Pennsylvania. (May 27-31, 2008) With M. Cannon, Y. Liu

     
     

    "Ionization of Xe(nf) Rydberg atoms at surfaces: Effect of stray fields." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, State College, Pennsylvania. (May 27-31, 2008) With D. D. Neufeld, H. R. Dunham, S. Wethekam, J. C. Lancaster

     
     

    "Realization of Bohr-like circular wavepackets." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, State College, Pennsylvania. (May 27-31, 2008) With J. J. Mestayer, B. Wyker, C. O. Reinhold, S. Yoshida and J. Burgdörfer

     
     

    "Transferring Rydberg wavepackets between islands across the chaotic sea." Division of Atomic, Molecular, and Optical Physics of the American Physical Society, State College, Pennsylvania. (May 27-31, 2008) With S. Yoshida, C. O. Reinhold, J. Burgdörfer. J. J. Mestayer, B. Wyker

     
     Posters
     

    Group leader.  "Creation, control, and detection of Rydberg excitations in ultracold strontium." American Physical Society, Division of Atomic, Molecular and Optical Physcis, Columbus, Ohio. (June 2015) With Joseph Whalen, Roger Ding, Francisco Camargo, German Woehl, Jr, Thomas Killian

     
     

    Group leader.  "Heavy-Rydberg ion-pair formation in Rydberg atom collisions: probing dissociative electron attachment." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With Michael Kelley, Sitti Buathong

     
     

    Group leader.  "New approaches for producing quantum degenerate gases of strontium." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With Roger Ding, Germano Woehl, Jr, Francisco Camargo, Joseph Whalen, Thomas Killian

     
     

    Group leader.  "Observation of Rydberg blockade effects at very high n, n~300 using strontium n1F3 states." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With Xinyue Zhang, Shuhei Yoshida, Joachim Burgdörfer

     
     

    Group leader.  "Producing quantum degenerate gases of strontium." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With Francisco Camargo, Roger Ding, Joseph Whalen, Germano Woehl, Thomas Killian

     
     

    Group leader.  "Rydberg blockade effects on Autler-Townes spectra in a dense gas of 84Sr." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With B. J. DeSalvo, J. A. Aman, T. C. Killian

     
     

    Group leader.  "Strongly-coupled high-n Rydberg atom pairs." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With Shuhei Yoshida, Joachim Burgdörfer, Xinyue Zhang

     
     

    Group leader.  "Trap losses induced by Rydberg dressing of cold atomic gases." American Physical Society, Division of Atomic, Molecular and Optical Physics, Columbus, Ohio. (June 2015) With J. A. Aman, B. J. DeSalvo, T. C. Killian

     
     

    Presenter.  "An experimental apparatus for studying Rydberg-Rydberg interactions in quantum degenerate gases of strontium." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With Francisco Camargo, Roger Ding, James Aman, Xinyue Zhang, Joseph Whalen, Robert Fields, Thomas Killian

     
     

    Presenter.  "Characterizing high-n quasi-one-dimensional strontium Rydberg atoms." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With Moritz Hiller, Shuhei Yoshida, Joachim Burgdörfer, Shuzhen Ye, Xinyue Zhang

     
     

    Presenter.  "Efficient three-photon excitation of quasi-1D n~300 strontium Rydberg atoms." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With Xinyue Zhang, Shuzhen Ye, Shuhei Yoshida, Moritz Hiller, Joachim Burgdörfer

     
     

    Presenter.  "Exploring dipole blockade using high-n strontium Rydberg atoms." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With Xinyue Zhang, Shuzhen Ye, Moritz Hiller, Shuhei Yoshida, Joachim Burgdörfer

     
     

    Presenter.  "Formation of heavy-Rydberg ion-pair states in Rydberg atom collisions with attaching targets." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With Changhao Wang, Michael Kelley, Sitti Buathong

     
     

    Presenter.  "Rydberg excitation in a Sr BEC." Division of Atomic, Molecular, and Optical Physics, American Physical Society, Madison, Wisconsin. (Jun 2-6, 2014) With B. J. DeSalvo, J. A. Aman, X. Zhang, T. Langin, T. C. Killian

     
     

    Presenter.  "Ultralong-range Rydberg molecules of strontium." 24th International Conference on Atomic Physics, Washington, D.C.. (Presenter) With B. J. DeSalvo, J. A. Aman, T. C. Kilian

     
     

    "Creation of quasi-one-dimensional high-n strontium Rydberg atoms." XXVIII International Conference on Photonic, Electronic and Atomic Collisions, Lanzhou, China. (July 2013)

     
     

    "Exciting and probing polarized strontium Rydberg atoms." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013) With Moritz Hiller, Shuhei Yoshida, Joachim Burgdorfer, Shuzhen Ye, Xinyue Zhang

     
     

    "Formation of heavy-Rydberg ion pairs in collisions between Rydberg atoms and attaching targets." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013) With Changhao Wang, Michael Kelley

     
     

    "Imaging the evolution of an ultracold strontium Rydberg gas." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013) With Xinyue Zhang, Patrick McQuillen, Trevor Strickler, Thomas Killian

     
     

    "Production of high-n strontium Rydberg atoms." XXVIII International Conference on Photonic, Electronic and Atomic Collisions, Lanzhou, China. (July 2013) With S. Ye, T.C. Killian, M. Hiller, S. Yoshida, J. Burgdorfer

     
     

    "Production of very-high-n strontium Rydberg atoms." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013) With Shuzhen Ye, Xinyue Zhang, Thomas Killian, Moritz Hiller, Shuhei Yoshida, Joachim Burgdorfer

     
     

    "Stabilizing Bohr wavepackets by electron-electron interaction." American Physical Society, Division of Atomic, Molecular & Optical Physics, Quebec City, Canada. (June 2013) With M. Scheucher, D. Wirtitsch, M. Hiller, S. Yoshida, J. Burgdorfer, S. Ye, X. Zhang

     
     

    "Chaotic energy hopping in bidirectionally kicked Rydberg atoms." 43rd Annual Meeting of the APS, Division of Atomic, Molecular and Optical Physics, Anaheim, California. (June 2012) With Korana Burke, Kevin Mitchell, and Shuzhen Ye

     
     

    "Creating and transporting Trojan wave packets." 43rd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Anaheim, California. (June 2012) With S. Ye, B. Wyker, X. Zhang, S. Yoshida, C.O. Reinhold, and J. Burgdörfer

     
     

    "Heavy-Rydberg ion-pair formation in collisions of Rydberg atoms with attaching targets." 43rd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Anaheim, California. (June, 2012) With Changhao Wang and Michael Kelley

     
     

    "Ionization of Rydberg atoms in controlled surface electric fields." 43rd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Anaheim, California. (June 2012) With Yu Pu

     
     

    Ionization of kicked Rydberg atoms via a turnstile mechanism. Chaos and Complexity Conference, Ann Arbor, Michigan. (May 2012) With K Burke, S Ye and B Wyker

     
     

    "Photoexcitation of high-n, n~300, Rydberg states in the presence of an rf driving field near the final Kepler frequency." 43rd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Anaheim, California. (June 2012) With S. Ye, X. Zhang, S. Yoshida, and J. Burgdörfer

     
     

    "Decoherence of high-l Rydberg wave packets by collisions and electrical noise." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With B. Wyker, S. Ye, T.J. McKinney, C. O. Reinhold, S. Yoshida, and J. Burgdörfer

     
     

    "Decoherence of high-n, high-l Rydberg wave packets by electrical noise and collisions." International Conference on Photonic, Electronic and Atomic Collisions, Queen's University, Belfast. (July 2011) With S. Yoshida, C. O. Reinhold, J. Burgdörfer, B. Wyker, and S. Ye

     
     

    "Direct experimental observations of a phase space turnstile in a Rydberg system." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With Kevin Mitchell, Korana Burke, Shuzen Ye, and Brendan Wyker

     
     

    "Electric-field-induced dissociation of heavy Rydberg ion-pair states." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With Carlos Reinhold, Shuhei Yoshida, and Changhao Wang

     
     

    "Field-induced dissociation of Rydberg ion-pair states." International Conference on Photonic, Electronic and Atomic Collisions, Queen's University, Belfast. (July 2011) With C. O. Reinhold and S. Yoshida

     
     

    "Ionization of kicked Rydberg atoms via a turnstile mechanism." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With Korana Burke, Kevin Mitchell, Shuzhen Ye, and Brendan Wyker

     
     

    "Probing and manipulating high-n near-circular Rydberg wave packets." International Conference on Photonic, Electronic and Atomic Collisions, Queen's University, Belfast. (July 2011) With B. Wyker, S. Ye, S. Yoshida, C. O. Reinhold, and J. Burgdörfer

     
     

    "Probing surface patch fields with Rydberg atoms." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With Yu Pu and Dean Neufeld

     
     

    "Transporting near-circular Bohr-like wave packets using chirped pulse trains." 2011 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Atlanta, Georgia. (June 2011) With S. Yoshida, J. Burgdörfer, C. O. Reinhold, B, Wyker, and S. Ye

     
     

    "Transporting near-circular Bohr-like wave packets using chirped sine waves." International Conference on Photonic, Electronic and Atomic Collisions, Queen's University, Belfast. (July 2011) With B. Wyker, S. Ye, S. Yoshida, C. O. Reinhold, and J. Burgdörfer

     
     

    "Encoding and decoding information in high-n circular wave packets." 2010 Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Houston, TX. (May 2010) With S. Yoshida, C. O. Reinhold, J. Burgdörfer, B. Wyker

     
     

    "Precise manipulation of Rydberg wave packets." 2010 Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Houston, TX. (May 2010) With C. O. Reinhold, S. Yoshida, J. Burgdörfer

     
     

    "Properties of heavy Rydberg ion-pair states formed in collisions between K(np) Rydberg atoms and attaching targets." 2010 Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Houston, TX. (May 2010) With M. Cannon, C. H. Wang

     
     

    The influence of stray fields on the ionization of Rydberg atoms at metallic surfaces - 2010 Annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, Houston, TX (with Dennis Neufeld and Yu Pu)

     
     

    "Creation of non-dispersive Bohr-like wave packets." 40th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, University of Virginia, Charlottesville, Virginia. (July 2009) With Jeff Mestayer, B. Wyker, C. O. Reinhold, S. Yoshida, J. Burgdörfer

     
     

    "Creation of non-dispersive Bohr-like wavepackets." 26th International Conference on Photonic, Electronic, and Atomic Collisions, Kalamazoo, Michigan. (July 2009) With J. J. Mestayer, B. Wyker, S. Yoshida, C. O. Reinhold, J. Burgdörfer

     
     

    "Formation of heavy Rydberg ion-pair states in collisions of K(np) Rydberg atoms with attaching targets." 40th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, University of Virginia, Charlottesville, Virginia. (July 2009) With M. Cannon, C. Wang

     
     

    "Ionization of Rydberg atoms at metal surfaces." 40th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, University of Virginia, Charlottesville, Virginia. (May 2009) With Dennis Neufeld, Yu Pu

     
     

    "Long-time quantum coherence of near-circular wavepackets." 26th International Conference on Photonic, Electronic, and Atomic Collisions, Kalamazoo, Michigan. (July 2009) With S. Yoshida, C. O. Reinhold, J. Burgdörfer, J. J. Mestayer, B. Wyker

     
     

    "Observation of quantum revivals in very-high-n atoms." 40th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society, University of Virginia, Charlottesville, Virginia. (July 2009) With Brendan Wyker, J. J. Mestayer, C. O. Reinhold, S. Yoshida, J. Burgdörfer

     
     

    "Production of heavy-Rydberg ion-pair states in Rydberg atom collisions." 26th International Conference on Photonic, Electronic, and Atomic Collisions, Kalamazoo, Michigan. (July 2009) With M. Cannon, C. Wang

     
     Seminar Speaker
     

    speaker.  "Strontium Rydberg atoms: Opportunities and challenges." University of Texas at Austin, Austin, Texas. (April 2015)

     
     

    speaker.  "Engineering near-circular high-n wavepackets." Durham University, Durham, England. (February 2011)

     
     

    speaker.  "Ultra-fast physics in the ns regime." Kansas State University, Manhattan, Kansas. (April 2011)

     
     

    "Designer atoms: Engineering Rydberg atoms using pulsed electric fields." University of Belfast, Belfast, Northern Ireland. (May 2009)

     
     

    "Generation of localized "Bohr-like" wavepackets in high-n Rydberg atoms." Rice University, Houston, Texas. (September 2009)

     
     

    "Behavior of Rydberg atoms at metal and semiconductor surfaces." Kansas State University, Manhattan, Kansas. (April 2008)

     
     

    "Designer atoms: Engineering Rydberg atoms using pulsed electric fields." Kansas State University, Manhattan, Kansas. (April 2008)

     
     

    "Designer atoms: Engineering Rydberg atoms using pulsed electric fields." Northwestern University, Chicago, IL. (May 2008)

     
     

    "Designer atoms: Engineering Rydberg atoms using pulsed electric fields." University of Durham, Durham, England. (March 2008)

     
     Workshops
     

    speaker.  "Strontium Rydberg atoms:  Opportunities and challenges." Exploratory workshop - Rydberg Physics with two-electron systems/University of Hamburg, Hamburg, Germany. (February 2015)

     
    Supervised Theses & Dissertations
     Matthew Cannon, MS The effect of internal energy on the lifetime of SF6- negative ions. (2007) (Thesis or Dissertation Director)

     Dennis Dean Neufeld, MS An ultra-compact retarding potential Mott polarimeter. (2007) (Thesis or Dissertation Director)

     Wei Zhao, PhD Engineering atomic wavepackets in very-high-n Rydberg atoms. (2007) (Thesis or Dissertation Director)

     Hardin Dunham, PhD Angular dependence of xenon Rydberg atom ionization at conducting and semiconducting surfaces. (2007) (Thesis or Dissertation Director)

     Yi Liu, PhD Study of dipole-bound negative ions: formational dynamics and collisional properties. (2007) (Thesis or Dissertation Director)

     Brendan Wyker, M.S. Realization of the Bohr atom. (2008) (Thesis or Dissertation Director)

     Jeffery Mestayer, PhD "Rydberg atom wavepacket dynamics in one- and two-dimensions". (2009) (Thesis or Dissertation Director)

     Dennis Neufeld, Ph.D. Interaction of xenon Rydberg atoms with conducting surfaces: the effects of stray fields. (2010) (Thesis or Dissertation Director)

     Changhao Wang, M.Sc. Lifetimes of weakly bound heavy-Rydberg ion-pair states formed through Rydberg atom collisions with attaching targets. (2010) (Thesis or Dissertation Director)

     Matt Cannon, Ph.D. Collisional formation of heavy Rydberg ion-pair states. (2010) (Thesis or Dissertation Director)

     Brendan Wyker, PhD High angular momentum Rydberg wave packets. (2011) (Thesis or Dissertation Director)

     Shuzhen Ye, MS Chaotic ionization of a Rydberg atom subjected to alternating kicks. (2011) (Thesis or Dissertation Director)

     Yu Pu, PhD Ionization of Rydberg atoms at patterned electrode arrays. (2013) (Thesis or Dissertation Director)

     Xinyue Zhang, MS Creating strontium Rydberg atoms. (2013) (Thesis or Dissertation Director)

     Michael Kelley, MS Dynamics of ion-pair formation in K(14p,20p)-SF6, CCl4 collisions. (2014) (Thesis or Dissertation Director)

     Shuzhen Ye, PhD Experimental study of potassium and strontium Rydberg atoms - chaotic ionization, quantum optical phenomena and multiphoton excitation. (2014) (Thesis or Dissertation Director)

     Sitti Buathong, MS title needed. (2015) (Thesis or Dissertation Director)

     Gavin Fields, MS Studies with strontium Rydberg atoms. (2015) (Thesis or Dissertation Director)

     Changhao Wang, PhD Dynamics and dissociation of collisionally formed heavy Rydberg ion pair states. (2015) (Thesis or Dissertation Director)

    Awards, Prizes, & Fellowships
     Outstanding Associate - Jones College, Jones College, Rice (Spring 2013)