Bulletin of the American Physical Society
2013 Joint Meeting of the APS Division of Atomic, Molecular & Optical Physics and the CAP Division of Atomic, Molecular & Optical Physics, Canada
Volume 58, Number 6
Monday–Friday, June 3–7, 2013; Quebec City, Canada
Session N6: Quantum Cavities and Resonators |
Hide Abstracts |
Chair: Stephan Ritter, Max Planck Institute for Quantum Optics Room: 302 |
Thursday, June 6, 2013 10:30AM - 10:42AM |
N6.00001: Control of conditional quantum beats in cavity QED Andres Cimmarusti, Wanderson Pimenta, Burkley Patterson, Luis Orozco, Pablo Barberis-Blostein, Howard Carmichael We present a feedback mechanism to preserve the Zeeman coherence of a conditional ground state superposition. We monitor the state by looking at quantum beats generated on the second order correlation function of the output of a driven two-mode cavity QED system. The decoherence is produced by phase diffusion due to Rayleigh scattering. We show how to prevent a shift in the Larmor frequency associated with this scattering. The protocol consists of turning off the drive of the system after the detection of a first photon and letting it evolve in the dark. Restoring the drive after a set time shows phase accumulation only from Larmor precession, and the amplitude of the quantum beat can increase by more than a factor of two with respect to continuous drive. We are exploring other protocols that rely on postselection. [Preview Abstract] |
Thursday, June 6, 2013 10:42AM - 10:54AM |
N6.00002: Cavity QED systems simulating field theories using Continuous Matrix Product States (cMPS) as variational states Aizar Enciso Dominguez, Sean Barrett, David Jennings The methods to understand quantum many body systems have been based in the proper representations of their ground states such as Matrix Product States (MPS). Those techniques have been recently extended to describe the low energy states of quantum field theories (QFTs), which involve infinite dimensional objects described in a continuous region of space. The resulting many-body variational wave functions (for 1-D field theories) are known as Continuous Matrix Product States (CMPS). They can be understood as the quantum fields that arise when a system with a finite number of levels (e.g. an atom) is allowed to interact, sequentially, with a quantum field (e.g. light in the cavity) at different points in 1-D space. The internal Hamiltonian of this finite system, and it's coupling to the 1-D field, are treated as variational parameters that allow a succinct description of the state of the field. Based on a recent connection made by Verstraete between CMPS's, and the states that are output from an optical cavity we are looking to simulate the response of one dimensional gases with optical cavities by connecting the CMPS that describe the gas with the physical variables involved in the description of the internal dynamics of the cavity. Indeed, the input-output formalism, for describing the quantum state of the field leaking out of a cavity bears similarities with the equations describing a CMPS. [Preview Abstract] |
Thursday, June 6, 2013 10:54AM - 11:06AM |
N6.00003: Optimal Control Functions of Photon Fock States in a Cavity Byron Lowry, Bereket Berhane, Sergey Drakunov The ability to control quantum mechanical states is an essential requirement for many experiments in fundamental quantum mechanics and applications in quantum information systems.~ Controllability for an atom in a cavity has been shown, and experimental techniques for controlling Fock states in a cavity have been displayed.~ However, a classical control theoretic treatment of an atom in a cavity has not been developed.~ From methods in quantum control theory, we develop optimal control functions for an atom in a cavity for different constraints and cost functions.~~ [Preview Abstract] |
Thursday, June 6, 2013 11:06AM - 11:18AM |
N6.00004: Experimental verification of light shift imbalance induced blockade in an atomic ensemble via collective state Rabi oscillation and coincidence detection May Kim, Yanfei Tu, Subramanian Krishnamurthy, Selim Shahriar For quantum computing with single atoms, it is necessary to have a single-photon Rabi frequency that is much stronger than the decay rates. This requires extremely small cavities, making it difficult to realize a quantum computer containing a large number of qubits, each held by a dipole trap. This constraint can be alleviated by employing collective excitation of N-atoms for each qubit, for which the single-photon Rabi frequency is enhanced by root-N, thus allowing the use of a larger cavity which can accommodate a significant number of such qubits. An explicit realization of a C-NOT gate for such a qubit uses Raman transitions, involving a single photon on one leg and a classical field on the other. This leads to a cascade of higher order collective states, which have to be suppressed. Previously, we had proposed the process of light-shift imbalanced induced blockade (LIB) to achieve this suppression. In this talk, we present a scheme for demonstrating LIB by detecting Raman-Rabi oscillations in a lambda system and coincidence detection in a Hanbury-Brown-Twiss setup. We present results of numerical simulations and describe experimental efforts for this demonstration. [Preview Abstract] |
Thursday, June 6, 2013 11:18AM - 11:30AM |
N6.00005: Possibility of cavity optomechanical phase shifts at the single photon level Julio Gea-Banacloche The dispersive bistability of a cavity optomechanical system could be exploited to imprint different phase shifts on pulses containing different numbers of photons. These phase shifts could, in turn, be used for quantum logical operations. Analytical and numerical results for a weak classical field will be presented that show the scheme is at least conceptually feasible; however, relatively fast damping of the movable mirror and careful shaping of the pulses appear to be crucial in order to obtain large (classical) fidelities. Calculations for quantized single- and two-photon pulses will also be presented and discussed. [Preview Abstract] |
Thursday, June 6, 2013 11:30AM - 11:42AM |
N6.00006: Phononic Phase Conjugation in an Optomechanical System Lukas Buchmann, Ewan Wright, Pierre Meystre We study theoretically the phase conjugation of a phononic field in an optomechanical system with two mechanical modes coupled to a common optical field. Phase conjugation becomes the dominant process for an appropriate choice of driving field parameters, and he effective coupling coefficients between phonon modes can result in amplification and entanglement, phase-conjugation or a mixture thereof. We discuss surprising consequences of mechanical phase-conjugation that could lead to the preparation of mechanical states with negative temperature, the improvement of quantum memories and the study of the quantum-classical transition. [Preview Abstract] |
Thursday, June 6, 2013 11:42AM - 11:54AM |
N6.00007: Efficient Guidance of Higher Order Modes in Subwavelength Optical Nanofiber Waveguides J.E. Hoffman, S. Ravets, P. Kordell, L.A. Orozco, S.L. Rolston, G. Beadie, F. Fatemi Optical nanofibers show great promise in the design, integration, and interconnection of nanophotonic devices. When the diameter of the waveguide becomes smaller than the wavelength, there exists an intense evanescent component propagating outside of the waveguide, providing a platform for probing non-linear physics or light-matter interaction. Previous work has seen high transmission of the fundamental mode through such waveguides. Working with higher-order modes allows the use of a larger nanofiber diameter than the fundamental mode regime, increasing robustness. Mode interference can produce unusual field distributions on the waist of the fiber, which may be of interest for atom trapping. In this talk, we demonstrate transmissions of 92\% for the first family of excited modes through an optical nanofiber with a radius of 400 nm. We achieve efficient guidance by choosing a fiber with a reduced cladding radius, which allows for a less stringent adiabatic condition as there are fewer modes to couple to in the waveguide. Additionally, controlling the angle of the taper geometries allows us to better meet the adiabatic criterion. We present a novel spectrogram measurement of mode beating during the fiber pull that allows characterization of the modes excited. [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