| February |
2006
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| Wed. 2/8/06 |
Joerg Schmiedmayer, The Universitaet Heidelberg,
"Coherent Manipulation of Matter waves on Atom Chips"
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| Wed. 2/22/06 |
Paola Cappellaro, MIT,
"Entanglement assisted measurement of a single spin".
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| March |
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| Wed. 3/1/06 |
Gerard Milburn, The University of Queensland
"Photons as qubits"
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| April |
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Wed. 4/12/06 |
Ana-Maria Rey, ITAMP,
"Quantum coherence of Hard-Core-Bosons and Fermions: Extended, Glassy and Mott Phases"
Abstract: Disorder has drastic effects in quantum systems of fermions and bosons. For non-interacting particles it leads to Anderson localization and to a metal-insulator transition. When interactions are present, the effects are even more drastic and the different phases induced by the interplay between disorder and interactions has been a topic of continuous theoretical interest. Cold atoms confined by a periodic lattice offer a unique laboratory to explore disordered systems in a controlled manner. I will discuss the use of Hanbury-Brown-Twiss interferometry (HBTI) to study various quantum phases of hard core bosons (HCBs) and ideal fermions confined in a one-dimensional lattice plus an additional quasi-periodic (QP) potential introduced to add pseudo-random disorder. In particular I will show the QP potential induces for HCBs a cascade of Mott-like band-insulator phases, in addition to the Mott insulator, Bose glass, and superfluid phases. I will discuss why HBTI can be used as a practical method to determine the phase diagram of the system.
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Wed. 4/26/06 |
Seth Lloyd, MIT,
"A Theory of Quantum Gravity Based on Quantum Computation"
Abstract: This talk proposes a theory of quantum gravity based on quantum information processing. In this theory, distances and time intervals are derived from pairwise interactions between quantum degrees of freedom: the geometry of spacetime is a construct, derived from the underlying quantum information processing. The theory provides explicit predictions for the back-reaction of the metric to computational `matter,' black-hole evaporation, holography, and quantum cosmology.
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| May |
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Wed. 5/10/06 |
Georg Raithel, University of Michigan,
"The Trapping and Interactions of Cold Rydberg Atoms"
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| September |
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| October |
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Wed. 10/04/06 |
Eugene Demler, Harvard University Physics
"Measuring correlation functions in interacting systems of cold atoms"
Abstract: I will discuss several approaches to measuring correlation functions in experiments with cold atoms. The first approach is based on analyzing atom shot noise in the time of flight experiments. I will review the connection of this approach to Hanburry-Brown-Twiss experiments and show that it can be used to probe novel quantum states of cold atoms including paired states of fermions and magnetically ordered states in optical lattices. Another approach that I consider relies on interference experiments between extended condensates. I will show that the intereference pattern contains information about correlation functions within individual condensates and that the full distribution of the fringe constrast provides information about high order correlation functions. I will also discuss how one can analyze spin systems realized with cold atoms using quantum fluctuations in the value of magnetization in a finite size system.
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Wed. 10/18/06 |
Marvin Girardeau, University of Arizona
"Exact Properties of Strongly Correlated Ultracold Gases in Tight Waveguides"
Abstract: The Fermi-Bose (FB) mapping, originally introduced to obtain exact ground and excited states of a 1D gas of impenetrable point bosons (TG gas), has been studied extensively following recent experimental realization of this strongly correlated system by ultracold gases in tight atom waveguides with e ective 1D interactions tunable via Feshbach resonances. A 1D spin-aligned Fermi gas with in nitely strong attractions (FTG gas) was solved recently by FB mapping, and its ground state was shown to have superconductive long-range order. These systems map exactly to ideal Fermi and Bose gases, the strong correlations being introduced by the mapping. I will describe the mapping and properties of these new states of matter. More generally, the FB mapping provides an exact connection between a 1D Bose gas with interactions of any strength and those of a spin-aligned Fermi gas, relating strongly interacting bosons to weakly interacting fermions and vice versa. Anyons interpolating continuously between bosons and fermions can be related exactly to fermions by a generalized mapping, and exact ground states of anyonic TG, FTG, and Calogero-Sutherland gases will be described, as will a spinor Fermi gas with anyonic symmetry under spatial exchange but normal Fermi antisymmetry under space-spin exchange, enabling energy lowering of an even number of such atoms in a ring trap by spin fips and anyonic phase slips.
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| November |
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Wed. 11/1/06 |
Anders Sorensen, Nils Bohr Institute
"Quantum Information Processing with dispersive interactions in atomic ensembles"
Abstract: In my talk I will discuss the theory we are developing in connection to the experimental activities in the group of Eugene Polzik at the Niels Bohr Institute. In these experiments a dispersive interaction between light and an atomic ensemble has been used to entangle two different atomic ensembles, implement a quantum memory, and most recently teleport a quantum state of light onto atoms. In my talk I will discuss the theory we are making to extend these application to an improved quantum memory, and realize long distance quantum communication. Furthermore, I will discuss a more detailed theoretical description of the interaction going on in these experiments. Whereas most descriptions of the interaction of light and atomic ensembles are carried out in a one-dimensional model, we have developed a full three dimensional description, which I will describe.
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Wed. 11/15/06 |
Dmitry Budker, UC-Berkeley
"Limit on the Temporal Variation of the Fine-Structure Constant Using Atomic Dysprosium"
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Wed. 11/29/06 |
Wonho Jhe, Seoul National University
"Nonlinear Dynamics and Critical Phenomena in Driven Cold Atoms".
Abstract:
Magneto-optical trap (MOT) has been one of the most widely used tools for atomic and optical physics. Because of its simplicity, accessibility, versatility, and controllability, it will continue to serve as a simple atomic model system for various fields of research. In this talk, we discuss some application of the simple MOT to study of interdisciplinary nature in statistical physics and condensed matter physics, such as nonlinear dynamics, Hopf bifurcation, phase transition, and nano physics.
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| December |
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Wed. 12/13/06 |
Thomas Pohl, ITAMP
"Forming, trapping, and cooling Rydberg antihydrogen in strong magnetic fields"
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