Bulletin of the American Physical Society
41st Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 55, Number 5
Tuesday–Saturday, May 25–29, 2010; Houston, Texas
Session R4: Matter Wave Guides and Interferometry |
Hide Abstracts |
Chair: Aaron Leanhardt, University of Michigan Room: Regencey Ballroom |
Friday, May 28, 2010 10:30AM - 10:42AM |
R4.00001: Quantum Tunneling of a Macroscopic Matter-wave Soliton S.E. Pollack, D. Dries, E.J. Olson, R.G. Hulet A fascinating property of many nonlinear wave equations is the existence of non-dispersive waves known as solitons, which provide unique possibilities in photonics as well as to investigate manifestations of quantum mechanics at the macroscopic scale. We create a stable bright matter-wave soliton consisting of ultracold $^7$Li atoms in an optical dipole trap, and offset it from the center of the trap by pulsing a magnetic field gradient. At the center of the trap we place a Gaussian barrier with a waist of comparable size to the nonlinear wave. By adjusting the velocity of the soliton and the height of the barrier we observe both reflection from and transmission through the barrier, as well as the splitting of the wave into two pieces. The two-piece object is allowed to complete an oscillation in the harmonic trap and reimpinge on the barrier, where it recombines. We report our results and discuss the possibilities of using this setup as a matter-wave beamsplitter for atom interferometry. [Preview Abstract] |
Friday, May 28, 2010 10:42AM - 10:54AM |
R4.00002: Optical vortices for angular diffraction of atoms Yisa Rumala, Charles Siedlecki, Aaron Leanhardt We interfere co-propagating, counter rotating optical vortices [1] in a modified Mach-Zehnder interferometer, and perform a detailed analysis of the interferometer as well as the transverse spatial mode profile. The imaging resolution and azimuthal fringe visibility of the interference pattern are experimentally and theoretically deduced. The angular variation of the transverse optical mode profile can be used as a Kapitza-Dirac phase grating to diffract atoms into different external angular momentum states, which may open up new possibilities for rotation sensing in ultra-cold atomic gases.\\[4pt] [1] J. Leach et al, Phys Rev Lett, 88, 257901 (2002) [Preview Abstract] |
Friday, May 28, 2010 10:54AM - 11:06AM |
R4.00003: Theoretical analysis of a free oscillation atom interferometer in a weakly confining magnetic trap Rudra Kafle, Dana Anderson, Alex Zozulya We analyze a Bose-Einstein Condensate (BEC)-based free oscillation atom Michelson interferometer in a weakly confining magnetic trap. A BEC at the center of a weakly confining magnetic trap is split into two harmonics by a laser standing wave. The harmonics move in opposite directions with equal speed and return under the influence of a harmonic trapping potential. They pass each other and return again, and they are recombined at the end of an interferometric cycle by a recombination pulse, which is identical to the splitting pulse. The visibility of the interferometer fringes is calculated by considering the change of the size of each harmonic. Our results show that the coherence time in the interferometer is improved in comparison to that of a double reflection interferometer, but the coherence time is degraded due to the change in size of the clouds. [Preview Abstract] |
Friday, May 28, 2010 11:06AM - 11:18AM |
R4.00004: Atom Interferometry Experiments in Fundamental Physics Shau-Yu Lan, Pei-Chen Kuan, Brian Estey, Cheong Chan, Holger Mueller Light-pulse atom interferometers have already been used to measure gravity, the fine structure constant, gravity gradients, and Newtons gravitational constant with high precision and accuracy. Recent developments like large-momentum transfer (LMT) beam splitters for matter waves, e.g. using a combination of Bloch oscillations and Bragg diffraction, increase the space-time area enclosed between the interferometer arms. This promises to boost the sensitivity of atom interferometer by several orders of magnitude. Furthermore, the common mode noise of interferometers can be removed by running a pair of conjugated interferometers simultaneously. Here, we report our recent progress of atom interferometer experiments. [Preview Abstract] |
Friday, May 28, 2010 11:18AM - 11:30AM |
R4.00005: Optimizing a trapped atom interferometer J. Grond, U. Hohenester, J. Schmiedmayer Interferometery with trapped Bose-Einstein condensates (BECs) offers new prospects for precision measurements. We analyse the limits of atom interferometry with split trapped BECs. The atom-atom interactions during the waiting stage (phase accumulation stage) of the interferometer limit the phase sensitivity. Number squeezing reduces phase diffusion in split Bose-Einstein condensates, phase squeezing would enhance the readout. We will discuss how to optimize the performance of a trapped atom interferometer and describe how to create the desired input states to optimize the phase sensitivity. These states can be prepared applying optimal control theory. To properly account for the many-body dynamics we perform calculations within the multi-configurational time dependent Hartree for Bosons (MCTDHB) method. [Preview Abstract] |
Friday, May 28, 2010 11:30AM - 11:42AM |
R4.00006: Supercritical superfluid and vortex unbinding following a quantum quench Ludwig Mathey, Anatoli Polkovnikov We study the dynamics of the relative phase of a bilayer of two-dimensional superfluids after the two superfluids have been decoupled. We find that on short time scales the relative phase shows `light cone' like thermalization and creates a metastable superfluid state, which can be supercritical. On longer time scales this state relaxes to a disordered state due to dynamical vortex unbinding. We study this effect both numerically using truncated Wigner approximation and analytically within a newly suggested time dependent renormalization group approach (RG). In particular, within RG we show that there are two possible fixed points for the real time evolution corresponding to the superfluid and normal steady states. So depending on the initial conditions and the microscopic parameters of the Hamiltonian the system undergoes a non-equilibrium phase transition of the Kosterlitz-Thouless type. The time scales for the vortex unbinding near the critical point are exponentially divergent, similar to the equilibrium case. [Preview Abstract] |
Friday, May 28, 2010 11:42AM - 11:54AM |
R4.00007: A circular dual BEC interferometer gyroscope Vanessa Leung, John Burke, Robert Horne, Robert Leonard, Charles Sackett Recently, gyroscopes based on ring-shaped condensate interferometers have been proposed [1]. They offer the advantages of long interaction times within confined physical dimensions. Phase errors can arise, however, from the technical difficulty of controlling noise effects such as mechanical vibrations, trap potential fluctuations, and initial condensate motion. To deal with these problems, we propose a gyroscope based on two dual interferometers consisting of condensates moving in a near-circular trajectory through a common harmonic potential. We show that in such a system, many sources of phase noise cancel to high order, with the primary limitation expected to be from residual asymmetry in the trapping potential. We will present theoretical results for noise sensitivity and our experimental progress towards implementing such a system. \\[4pt] [1] Burke, J. H. T. and C. A. Sackett, ``Scalable Bose-condensate Sagnac interferometer in a linear trap.'' \textit{Phys. Rev. A} \textbf{80 }061603(R) (2009) and references therein. [Preview Abstract] |
Friday, May 28, 2010 11:54AM - 12:06PM |
R4.00008: Optimization of an onboard atomic interferometer and a new technique of acceleration measurement with Bloch oscillations Ren\'ee Charriere, Olivier Carraz, Malo Cadoret, Nassim Zahzam, Yannick Bidel, Alexandre Bresson, Fran\c{c}ois Nez In the last years, great progresses have been achieved in the manipulation of De Broglie atomic waves by coherent light pulses. They make possible the realization of very sensitive atomic interferometers, such as gravimeters, gradiometers, or gyroscopes. We propose to realize an onboard atomic gravimeter. Such gravimeter has many applications: navigation by ground correlation, positioning with a gravity map, oil deposits or buried ruins localization by detection of gravity anomaly, test of the equivalence principle. The principle of an atomic gravimeter is as follows. The atoms are first cooled down. Then, while falling under the gravity, they are exposed to light pulses. The phase excursion between the two possible paths of the atoms is directly linked to the value of the gravity, and is also proportional to the fall distance of the atoms. Thus, a higher sensitivity of the measurement requires a higher interferometer height. A new measurement technique is currently being implemented. It will reduce the fall distance while keeping the same sensitivity: atoms are put in levitation into a vertical optical lattice where they make Bloch oscillations. We can thus make our gravimeter smaller, which is interesting for an onboard gravimeter. [Preview Abstract] |
Friday, May 28, 2010 12:06PM - 12:18PM |
R4.00009: Excitation of the TE$_{01}$ hollow metal waveguide mode for atom guiding Fredrik Fatemi, Mark Bashkansky, Doewon Park, Eunkeu Oh We demonstrate excitation of the azimuthally-polarized TE$_{01}$ cylindrical waveguide mode in hollow glass and metal waveguides with 780 nm light. We describe stable and efficient techniques for mode conversion of an incident Gaussian beam to a vectorial vortex beam, and measure attenuation lengths of the TE$_{01}$ mode in hollow optical fibers with diameters of 50-100 $\mu$m. By silver-coating the inner walls of the dielectric fibers, we demonstrate a $\sim$200\% increase in the attenuation length. We discuss progress in implementing these fibers into a cold atom system. [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