M. G. Boshier

Los Alamos National Laboratory, Los Alamos, California, United States

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Publications (75)136.73 Total impact

  • I. Savukov, T. Karaulanov, M.G. Boshier
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    ABSTRACT: Radio-frequency (RF) atomic magnetometers (AMs) can be used in many applications, such as magnetic resonance imaging and nuclear quadrupole resonance. High-density AMs provide both superior sensitivity and large bandwidth. Previously, high-density potassium AMs were demonstrated, but these magnetometers have various disadvantages, such as high-temperature of operation and bulky design. We demonstrate a rubidium-87 RF AM with 5 fT/Hz1/2 sensitivity (3 fT Hz1/2 probe noise), which is comparable to that of the best potassium magnetometers. Our magnetometer also features a simple fiber-optic design, providing maximum flexibility for magnetic-field measurements.
    Applied Physics Letters 01/2014; 104(2):023504-023504-3. · 3.79 Impact Factor
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    C. Ryu, K. C. Henderson, M. G. Boshier
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    ABSTRACT: Bessel beams are plane waves with amplitude profiles described by Bessel functions. They are important because they propagate ‘diffraction-free’ and because they can carry orbital angular momentum. Here we report the creation of a Bessel beam of de Broglie matter waves. The Bessel beam is produced by the free evolution of a thin toroidal atomic Bose-Einstein condensate (BEC) which has been set into rotational motion. By attempting to stir it at different rotation rates, we show that the toroidal BEC can only be made to rotate at discrete, equally spaced frequencies, demonstrating that circulation is quantized in atomic BECs. The method used here can be viewed as a form of wavefunction engineering which might be developed to implement cold atom matter wave holography.
    12/2013; 16(1).
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    Adolfo del Campo, Malcolm G. Boshier, Avadh Saxena
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    ABSTRACT: Non-zero curvature in a waveguide leads to the appearance of an attractive quantum potential which crucially affects the dynamics in matter-wave circuits. Using methods of supersymmetric quantum mechanics, pairs of bent waveguides are found whose geometry-induced potentials share the same scattering properties. As a result, reflectionless waveguides, dual to the straight waveguide, are identified. Strictly isospectral waveguides are also found by modulating the depth of the trapping potential. Numerical simulations are used to demonstrate the efficiency of these approaches.
    Scientific reports. 11/2013; 4.
  • A. A. Blinova, M. G. Boshier, Eddy Timmermans
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    ABSTRACT: We show that repulsive neutral-atom impurities in a dilute gas Bose-Einstein condensate (BEC) can self-localize in bubble polaron states formally analogous to electron bubbles in helium. The BEC is then the first impurity host medium known to exhibit both Landau-Pekar polaron states akin to that of self-localized electrons in a dielectric lattice and self-localized bubble polaron states. We find that the neutral BEC-impurity system is fully characterized by only two dimensionless coupling constants and that a single BEC impurity can be steered adiabatically from the Landau-Pekar to the bubble region. The adiabatic change is that of a crossover, not a transition.
    Physical Review A 11/2013; 88(5). · 3.04 Impact Factor
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    ABSTRACT: We report the creation of ideal Josephson junctions in a toroidal dilute gas Bose-Einstein condensate (BEC). The demonstrated configuration of a pair of junctions on a multiply-connected BEC is the cold atom analog of the well-known dc Superconducting Quantum Inteference Device (SQUID). We measure the critical current of the junctions, observe Josephson effects, and find dynamic behavior that is in good agreement with the simple Josephson equations for an ideal tunnel junction with a sinusoidal current-phase relation. The junctions and toroidal trap are created with the Painted Potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single Atom-SQUID case reported here. Since rotation plays the same role in the Atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor. It may also be useful for creating macroscopic Schr\"odinger Cat states.
    Physical Review Letters 04/2013; 111(20). · 7.73 Impact Factor
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    A. A. Blinova, M. G. Boshier, Eddy Timmermans
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    ABSTRACT: Polarons, self-localized composite objects formed by the interaction of a single impurity particle with a host medium, are a paradigm of strong interaction many-body physics. We show that dilute gas Bose-Einstein condensates (BEC's) are the first medium known to self-localize the same impurity particles both in a Landau-Pekar polaron state akin to that of self-localized electrons in a dielectric lattice, and in a bubble state akin to that of electron bubbles in helium. We also show that the BEC-impurity system is fully characterized by just two dimensionless coupling constants, and that it can be adiabatically steered from the Landau-Pekar regime to the bubble regime in a smooth crossover trajectory.
    04/2013;
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    A Del Campo, M G Boshier
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    ABSTRACT: A method is proposed to drive an ultrafast non-adiabatic dynamics of an ultracold gas trapped in a time-dependent box potential. The resulting state is free from spurious excitations associated with the breakdown of adiabaticity, and preserves the quantum correlations of the initial state up to a scaling factor. The process relies on the existence of an adiabatic invariant and the inversion of the dynamical self-similar scaling law dictated by it. Its physical implementation generally requires the use of an auxiliary expulsive potential. The method is extended to a broad family of interacting many-body systems. As illustrative examples we consider the ultrafast expansion of a Tonks-Girardeau gas and of Bose-Einstein condensates in different dimensions, where the method exhibits an excellent robustness against different regimes of interactions and the features of an experimentally realizable box potential.
    Scientific Reports 01/2012; 2:648. · 5.08 Impact Factor
  • Changhyun Ryu, Kevin Henderson, Malcolm Boshier
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    ABSTRACT: Quantized circulation, one of the most important consequences of Bose-Einstein condensation, is fundamental to the understanding of superfluid phenomena. In a toroidal trap, Bose- condensed atoms should flow with a well defined winding number, which makes it an ideal system to demonstrate the quantized nature of circulation. We used a scanning laser beam to create a toroidal trap [1]. To rotate the atoms, a small potential barrier within the toroidal trap was rotated at a certain frequency and then the barrier was lowered to create a quantized flow state. The winding number of the flow was determined by the diameter of the central hole seen in a time of flight image of the condensate. The measurement showed diameters increasing stepwise with the stirring frequency. We observed flows with winding number up to 5. This is a clear demonstration of the quantization of the flow of atoms in a toroidal trap. Further study of critical velocity and metastability of flow of atoms will be very important in understanding the nature of superfluidity of atoms in a toroidal trap, especially in a 1D limit.[4pt] [1] K. Henderson, C. Ryu, C. MacCormick, and M. G. Boshier, New Journal of Physics 11, 043030 (2009).
    03/2010;
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    ABSTRACT: We describe a method ootnotetextT. E. Wall et al., Phys. Rev. A 78, 062509 (2008) for determining the radiative decay properties of a molecule by studying the saturation of laser-induced fluorescence and the associated power broadening of spectral lines. The fluorescence saturates because the molecules decay to states that are not resonant with the laser. The amplitudes and widths of two hyperfine components of a spectral line are measured over a range of laser intensities and the results compared to a model of the laser-molecule interaction. Using this method we measure the lifetime of the A(v'=0) state of CaF to be tau=19.2±0.7 ns, and the Franck-Condon factor for the transition to the X(v=0) state to be Z=0.987-0.019^+0.013. In addition, our analysis provides a measure of the hyperfine interval in the lowest-lying state of A(v'=0), deltae=4.8±1.1 MHz. A Franck-Condon factor close to 1 opens the possiblity of implementing a cycling transition with a small number of additional repump frequencies. We discuss possible schemes of laser cooling CaF or other alkaline earth monofluorides.
    05/2009;
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    K. Henderson, C. Ryu, C. MacCormick, M. G. Boshier
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    ABSTRACT: There is a pressing need for robust and straightforward methods to create potentials for trapping Bose-Einstein condensates which are simultaneously dynamic, fully arbitrary, and sufficiently stable to not heat the ultracold gas. We show here how to accomplish these goals, using a rapidly-moving laser beam that "paints" a time-averaged optical dipole potential in which we create BECs in a variety of geometries, including toroids, ring lattices, and square lattices. Matter wave interference patterns confirm that the trapped gas is a condensate. As a simple illustration of dynamics, we show that the technique can transform a toroidal condensate into a ring lattice and back into a toroid. The technique is general and should work with any sufficiently polarizable low-energy particles. Comment: Minor text changes and three references added. This is the final version published in New Journal of Physics
    New Journal of Physics 02/2009; · 4.06 Impact Factor
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    ABSTRACT: We describe a method for determining the radiative decay properties of a molecule by studying the saturation of laser-induced fluorescence and the associated power broadening of spectral lines. The fluorescence saturates because the molecules decay to states that are not resonant with the laser. The amplitudes and widths of two hyperfine components of a spectral line are measured over a range of laser intensities and the results compared to a model of the laser-molecule interaction. Using this method we measure the lifetime of the A(v'=0) state of CaF to be tau=19.2 \pm 0.7 ns, and the Franck-Condon factor for the transition to the X(v=0) state to be Z=0.987 (+0.013 || -0.019). In addition, our analysis provides a measure of the hyperfine interval in the lowest-lying state of A(v'=0), Delta_e=4.8 \pm 1.1 MHz.
    Physical Review A 01/2008; 78(6). · 3.04 Impact Factor
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    ABSTRACT: We report progress towards making a precise measurement of the 2S Lamb shift in singly-ionised helium by spectroscopy of the 2S-3S transition. The motivation for the experiment is discussed with reference to recent developments in the theory of quantum electrodynamics (QED) and a description of the apparatus and techniques used is given.
    12/2007: pages 303-313;
  • M G Boshier
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    ABSTRACT: This paper discusses some recent and ongoing experiments involving the application of laser spectroscopy to light hydrogenic atoms. Several theoretical groups have recently made substantial advances in the calculation of energy level corrections due to quantum electrodynamics, the theory most directly tested by these experiments. At the same time optical spectroscopy of hydrogen has reached the point where uncertainties due to strong interactions are an important limitation in the interpretation of measurements. This problem is much less severe in the case of the singly-ionised He+ ion, motivating laser spectroscopic measurements of Lamb shifts in that system. New experiments on muonium complement this work on more conventional atoms.
    Physica Scripta 09/2006; 2000(T86):21. · 1.03 Impact Factor
  • A S Arnold, C MacCormick, M G Boshier
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    ABSTRACT: Adjustable magnetic reflection and focusing of an 87Rb Bose–Einstein condensate was achieved using a particularly smooth mirror and a very straightforward apparatus. In this paper, we discuss a simple Thomas–Fermi model and a Monte Carlo method for analysing the bouncing. Both models are in close agreement with the observed condensate evolution. Additionally, the theory predicts very tight condensate focusing, and atomic matter-wave diffraction should be observable. The effect of mirror anharmonicities on the condensate focusing is investigated.
    Journal of Physics B Atomic Molecular and Optical Physics 12/2003; 37(2):485. · 2.03 Impact Factor
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    A. S. Arnold, C. MacCormick, M. G. Boshier
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    ABSTRACT: We report adjustable magnetic `bouncing' and focusing of a dilute $^{87}$Rb Bose gas. Both the condensate production and manipulation are realised using a particularly straight-forward apparatus. The bouncing region is comprised of approximately concentric ellipsoidal magnetic equipotentials with a centre that can be adjusted vertically. We extend, and discuss the limitations of, simple Thomas-Fermi and Monte-Carlo theoretical models for the bouncing, which at present find close agreement with the condensate's evolution. Very strong focusing has been inferred and the observation of atomic matter-wave diffraction should be possible. Prospects look bright for applications in matter-wave atom-optics, due to the very smooth nature of the mirror.
    06/2003;
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    D. J. Berkeland, M. G. Boshier
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    ABSTRACT: We present a general discussion of the techniques of destabilizing dark states in laser-driven atoms with either a magnetic field or modulated laser polarization. We show that the photon scattering rate is maximized at a particular evolution rate of the dark state. We also find that the atomic resonance curve is significantly broadened when the evolution rate is far from this optimum value. These results are illustrated with detailed examples of destabilizing dark states in some commonly-trapped ions and supported by insights derived from numerical calculations and simple theoretical models. Comment: 14 pages, 10 figures
    Physical Review A 11/2001; · 3.04 Impact Factor
  • S.A. Hopkins, E.A. Hinds, M.G. Boshier
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    ABSTRACT: Magnetic videotape is of great interest for trapping and guiding cold atomic vapors, but was hitherto considered unsuitable for manipulating Bose–Einstein condensates (BEC) because of the presumed evolution of gas under vacuum. We have studied the outgassing in vacuum of the most promising tape, Ampex 398 Betacam SP. We find that after cleaning in ethanol and baking for 200h at 100°C the magnetic patterns are undisturbed and the outgassing is remarkably small: 4×10-10Torr l s-1cm-2, due mostly to hydrogen. This makes the tape exceedingly attractive for manipulation of BEC.
    Applied Physics B 06/2001; 73(1):51-54. · 1.78 Impact Factor
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    A. S. Arnold, C. MacCormick, M. G. Boshier
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    ABSTRACT: We report the reflection and focussing of a Bose-Einstein condensate by a new pulsed magnetic mirror. The mirror is adaptive, inelastic, and of extremely high optical quality. The deviations from specularity are less than 0.5 mrad rms, making this the best atomic mirror demonstrated to date. We have also used the mirror to realize the analog of a beam-expander, producing an ultra-cold collimated fountain of matter waves Comment: 4 pages, 4 figures
    Physical Review A 03/2001; · 3.04 Impact Factor
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    E A Hinds, C J Vale, M G Boshier
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    ABSTRACT: A versatile miniature de Broglie waveguide is formed by two parallel current-carrying wires in the presence of a uniform bias field. We derive a variety of analytical expressions to describe the guide and present a quantum theory to show that it offers a remarkable range of possibilities for atom manipulation on the submicron scale. These include controlled and coherent splitting of the wave function as well as cooling, trapping, and guiding. In particular, we discuss a novel microscopic atom interferometer with the potential to be exceedingly sensitive.
    Physical Review Letters 03/2001; 86(8):1462-5. · 7.73 Impact Factor
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    ABSTRACT: The 1s–2s energy interval in the muonium (μ+e−) atom has been measured by Doppler free two photon laser spectroscopy. A value of 2455528941.0(9.8) MHz has been obtained in good agreement with quantum electrodynamics (QED). The muon-electron mass ratio can be extracted and is found to be 206.76838(17). The measurement may also be interpreted as a determination of the muon-electron charge ratio as -1- 1.1(2.1)· 10−9. Corresponding measurements in deuterium using the same experimental setup confirmed the validity of the applied analysis procedure.
    Hyperfine Interactions 07/2000; 127(1):197-200. · 0.21 Impact Factor

Publication Stats

1k Citations
136.73 Total Impact Points

Institutions

  • 2008–2014
    • Los Alamos National Laboratory
      • • Applied Modern Physics Group
      • • Physics Division
      Los Alamos, California, United States
  • 1998–2007
    • University of Sussex
      • Department of Physics and Astronomy
      Brighton, England, United Kingdom
  • 1994–2000
    • Universität Heidelberg
      • • Institute of Physical Chemistry
      • • Institute of Physics
      Heidelberg, Baden-Wuerttemberg, Germany
  • 1991–1999
    • Yale University
      • Department of Physics
      New Haven, Connecticut, United States
  • 1988–1998
    • University of Oxford
      Oxford, England, United Kingdom