LPHYS'18.    Plenary Speakers:

  1. Laser-Plasma Accelerators for Colliders and Light Sources

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      Eric Esarey


      Lawrence Berkeley National Laboratory, Berkeley, CA, USA
    Abstract:

    Early in 2016 two US workshops were held with a primary objective of outlining a roadmap of the R&D required to realize a plasma-based collider. Highlights from this road mapping exercise will be presented and the basic physics [1] of plasma accelerators will be discussed. The roadmaps for both particle-beam-driven and laser-driven concepts contained many similarities and parallels, since much of the physics and required R&D are independent of driver. These parallels include the multiple staging of ~10-GeV level modules, the preservation of beam quality throughout multiple stages, mitigation of emittance growth due to collisions and ion motion, high efficiency acceleration, the difficulty of accelerating positrons with nonlinear plasma waves, the use of hollow plasma channels for positron acceleration, and the mitigation of transverse beam instabilities. Laser development is needed to provide the high average powers and high rep-rates required by a laser-plasma accelerator. Development of high-power optics technology (mirrors, diffraction gratings, beam combiners) to withstand 100s kW of optical power will be needed. In addition to the main linacs, R&D is required on other colliders components, such as beam cooling/damping systems and the final focus/beam delivery systems. Near-term and mid-tem applications for plasma-based accelerators were deemed an essential part of a collider R&D roadmap. These intermediate applications include drivers for novel radiation sources, such as x-ray free-electron lasers and gamma sources based on laser-electron beam scattering.

    Work supported by the US DOE under contract no. DE-AC02-05CH11231.

    References:
    1. [1] E Esarey, C B Schroeder and W P Leemans, Rev. Mod. Phys. 81, 1229 (2009)
  2. Quantum Gas in a Box

    Abstract:

    For the past two decades ultracold Bose and Fermi atomic gases have been used with great success to study fundamental many-body physics. While traditionally they were produced in harmonic electromagnetic traps, it recently also became possible to create them in the uniform potential of an optical box trap [1]. This has opened even more possibilities for fundamental studies, allowing closer connections with other many-body systems and the theories that rely on the translational symmetry of the system. Research topics for which the homogeneous, box-trapped quantum gases offer distinct advantages include critical phenomena near phase transitions [2], quantum turbulence [3], strongly-interacting gases [4,5], and searches for exotic states of matter that are expected to occur in tiny slivers of phase diagrams. I will give an overview of the progress in this growing field, focusing on the recent experiments from my group.

    References:
    1. [1] A L Gaunt, T F Schmidutz, I Gotlibovych, R P Smith and Z Hadzibabic, Phys. Rev. Lett. 110, 200406 (2013)
    2. [2] N Navon, A L Gaunt, R P Smith and Z Hadzibabic, Science 347, 167 (2015)
    3. [3] N Navon, A L Gaunt, R P Smith and Z Hadzibabic, Nature 539, 72 (2016)
    4. [4] R Lopes, C Eigen, N Navon, D Clément, R P Smith and Z Hadzibabic, Phys. Rev. Lett. 119, 190404 (2017)
    5. [5] C Eigen, J A P Glidden, R Lopes, N Navon, Z Hadzibabic and R P Smith, Phys. Rev. Lett. 119, 250404 (2017)
  3. Isotopically Purified Crystals for Optical Quantum Memory

    Abstract:

    Quantum memories are of crucial importance for developing quantum information technologies and form a platform for creating scalable linear optical quantum computers, realizing long-distance quantum communication, making deterministic single-photon and multiphoton sources, and some other applications. Currently, one of the most commonly discussed materials for quantum storage are rare-earth-ion-doped solids. Among them, isotopically purified crystals are of particular interest. They can demonstrate very small inhomogeneous broadening of optical transitions, reaching 10 MHz, which proves to be smaller than the hyperfine splitting of the energy levels of impurity ions, and provide high optical densities. As a result, these crystals are promising candidates for implementing quantum storage via off-resonant Raman absorption/emission of single photons and single-photon frequency conversion. In this presentation, I will give an overview of the recent progress in studying these materials and utilizing them for implementation of solid-state off-resonant Raman quantum memories.

  4. Probing Matter at the Spatio-Temporal Limits Using Coherent X-ray Beams from Tabletop Femtosecond Lasers

    Abstract:

    Ever since the invention of the laser over 50 years ago, scientists have been striving to create an X-ray version of the laser. Advances in extreme nonlinear optics now make it possible to coherently and efficiently upshift tabletop femtosecond lasers into the ultraviolet (EUV) and soft X-ray regions of the spectrum, to wavelengths as short as 8 Å, with pulse durations in the femtosecond to attosecond regime. This unique high harmonic (HHG) light source is ideally suited for probing and imaging the fastest charge and spin dynamics in materials [1-6]. Recent applications include the demonstration of the first full-field microscope with sub-wavelength spatial resolution at short wavelengths, surpassing the resolution of traditional microscopes by almost an order of magnitude. Other applications include quantifying how nanoscale energy flow differs from bulk, measuring how fast a material can change its electronic or magnetic state, probing how spin currents can control and enhance magnetization in ultra thin films, and distinguishing charge scattering and screening in materials on sub-femtosecond timescales.

    References:
    1. [1] C Chena Z Tao, A Carr, P Matyba, T Szilvási, S Emmerich, M Piecuch, M Keller, D Zusin, S Eich, M Rollinger, W You, S Mathias, U Thumm, M Mavrikakis, M Aeschlimann, P M Oppeneer, H Kapteyn and M Murnane, P. Natl. Acad. Sci. USA 114, E5300 (2017)
    2. [2] D F Gardner, M Tanksalvala, E R Shanblatt, X Zhang, B R Galloway, C L Porter, R Karl Jr, C Bevis, D E Adams, H C Kapteyn, M M Murnane and G F Mancini, Nat. Photonics 11, 259 (2017)
    3. [3] Z Tao, C Chen, T Szilvási, M Keller, M Mavrikakis, H Kapteyn and M Murnane, Science 353, 62 (2016)
    4. [4] T Fan, P Grychtol, R Knut, C Hernández-García, D D Hickstein, D Zusin, C Gentry, F J Dollar, C A Mancuso, C W Hogle, O Kfir, D Legut, K Carva, J L Ellis, K M Dorney, C Chen, O G Shpyrko, E E Fullerton, O Cohen, P M Oppeneer, D B Milošević, A Becker, A A Jaroń-Becker, T Popmintchev, M M Murnane and H C Kapteyn, P. Natl. Acad. Sci. USA 112, 14206 (2015)
    5. [5] D Popmintchev, C Hernández-García, F Dollar, C Mancuso, J A Pérez-Hernández, M-C Chen, A Hankla, X Gao, B Shim, A L Gaeta, M Tarazkar, D A Romanov, R J Levis, J A Gaffney, M Foord, S B Libby, A Jaron-Becker, A Becker, L Plaja, M M Murnane, H C Kapteyn and T Popmintchev, Science 350, 1225 (2015)
    6. [6] J Miao, T Ishikawa, I K Robinson and M M Murnane, Science 348, 530 (2015)
  5. Single Photons and Nonclassicality

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      Peter Knight


      Blackett Laboratory, Imperial College, London, UK
      Quantum Metrology Institute, National Physical Laboratory, Teddington, UK
    Abstract:

    Quantum Optics has focused for many years on uncovering what is specifically non-classical about light fields, from the early days of quantum mechanics to current work on quantum information processing. Much of this work has concentrated on the role of discreteness, of the limits of the uncertainty relation in governing fluctuations and the nature of quantum correlations beyond what is allowed classically. Progress in identifying, generating and characterizing nonclassical states has been spectacular. Quantum Information Science in part has grown out of this progress: the quantum world allows information to be encoded, manipulated and transmitted in ways quite different from classical physics. We will discuss the formation, propagation and manipulation of single photon wavepackets, explain how these can be used in simple quantum networks (for example in quantum walks and in Boson Sampling), and describe recent work on detecting single photons non-destructively.

    Detecting a single photon without absorbing it is a long-standing challenge in quantum optics. All experiments demonstrating the nondestructive detection of a photon make use of a high quality cavity. We present a cavity- free scheme for nondestructive single-photon detection. By pumping a nonlinear medium we implement an inter-field Rabi oscillation that leads to a ~ π-phase shift on a weak probe coherent laser field in the presence of a single signal photon without destroying the signal photon. This cavity-free scheme operates with a fast intrinsic time scale in comparison with similar cavity-based schemes.

  6. Controlling Atmospheric Processes with High Intensity Laser Filaments

    Abstract:

    Ultra-intense laser filaments have recently demonstrated their potential for modulating atmospheric processes [1]. Four characteristic examples are highlighted in the present presentation: lightning control, laser induced water vapour condensation, transmission of optical data through fog, and modulation of the radiative forcing properties of cirrus clouds. For instance, field experiments in various atmospheric conditions showed that laser filaments induce water vapour condensation and fast droplet growth up to several µm as soon as the relative humidity (RH) exceeds 70%. This effect mainly relies on photochemical mechanisms allowing efficient binary condensation and ultrafast oxidation of existing organic particles. Conversely, clearing fogs and clouds is efficiently achieved by using high average power (>100 W, >kHz) ultrashort, high intensity, lasers. Instead of evaporating the droplets, the mechanism relies on shock waves induced by the filaments that mechanically expel the droplets from the beam in a quasi-continuous way. The applications of such fog and cloud clearing are of paramount importance for recent programs on laser-based earth-to-satellite classical or quantum communications.

    References:
    1. [1] J P Wolf, Rep. Prog. Phys. 81, 026001 (2018)