Now showing items 452-467 of 467

  • Ultrafast charge generation in a semiconducting polymer studied with THz emission spectroscopy 

    Hendry, Euan; Koeberg, Mattijs; Schins, Juleon M.; Siebbeles, L. D. A.; Bonn, Mischa (American Physical Society, 2004)
    We study the ultrafast charge generation in a semiconducting polymer (MEH-PPV) by measuring the radiated THz field after photoexciting the biased polymer with a femtosecond visible pulse. The subpicosecond temporal ...
  • Ultrafast demagnetization of Co 25Ni 75/Pt multilayers with perpendicular anisotropy at elevated temperatures 

    Wilks, R.; Hicken, R.J.; Ali, M.; Hickey, B.J. (American Institute of Physics, 2005)
    Ultrafast demagnetization has been studied in Si/Pt(160 Å)/[Co25Ni75(x)/Pt(8 Å)]20 (x = 3, 4.5, and 6 Å) multilayers with perpendicular anisotropy by magneto-optical pump-probe measurements in the polar geometry. Time-resolved ...
  • Ultrafast magnetization dynamics of spintronic nanostructures 

    Keatley, Paul Steven; Kruglyak, V.V.; Gangmei, Prim; Hicken, R.J. (Royal Society, 2011)
    The ultrafast (sub-nanosecond) magnetization dynamics of ferromagnetic thin films and elements that find application in spintronic devices is reviewed. The major advances in the understanding of magnetization dynamics in ...
  • Ultrafast optical modification of magnetic anisotropy and stimulated precession in an epitaxial Co2 MnAl thin film 

    Liu, Y.; Shelford, L.R.; Kruglyak, V.V.; Hicken, R.J.; Sakuraba, Y.; Oogane, M.; Ando, Y.; Miyazaki, T. (American Institute of Physics, 2007)
    An all-optical pump-probe method was used to study magnetization precession in an epitaxial Co2MnAl Heusler alloy thin film. The frequency and amplitude of precession showed a clear fourfold variation as the orientation ...
  • Ultrafast optical switching of the THz transmission through metallic subwavelength hole arrays 

    Hendry, Euan; Lockyear, Matthew J.; Gómez Rivas, J.; Kuipers, L.; Bonn, Mischa (American Physical Society, 2007)
    We demonstrate ultrafast optical switching of the transmission of terahertz radiation through a metal grating with subwavelength holes. By fabricating the grating on a semiconductor silicon substrate, we are able to control ...
  • Ultrasensitive detection and characterization of biomolecules using superchiral fields 

    Hendry, Euan; Carpy, T.; Johnston, J.; Popland, M.; Mikhaylovskiy, Rostislav; Lapthorn, A.J.; Kelly, S.M.; Barron, L.D.; Gadegaard, N.; Kadodwala, M. (Nature Publishing Group, 2010)
    The spectroscopic analysis of large biomolecules is important in applications such as biomedical diagnostics and pathogen detection, and spectroscopic techniques can detect such molecules at the nanogram level or lower. ...
  • The upper atmosphere of the exoplanet HD 209458 b revealed by the sodium D lines. Temperature-pressure profile, ionization layer, and thermosphere 

    Vidal-Madjar, A.; Sing, David K.; Lecavelier des Etangs, A.; Ferlet, R.; Desert, J.-M.; Hebrard, G.; Boisse, I.; Ehrenreich, D.; Moutou, C. (EDP Sciences for European Southern Observatory (ESO), 2011)
    A complete reassessment of the Hubble Space Telescope (HST) observations of the transits of the extrasolar planet HD 209458 b has provided a transmission spectrum of the atmosphere over a wide range of wavelengths. Analysis ...
  • Urban form and function as building performance parameters 

    Futcher, Julie Ann; Kershaw, Tristan; Mills, Gerald (Elsevier, 2013)
    The climate in cities differs significantly from those found in the surrounding area. These differences results from modifications of the Earth's surface that alters the disposition of “natural energy balance” at a micro-scale ...
  • Use of microscale coplanar striplines with indium tin oxide windows in optical ferromagnetic resonance measurements 

    Keatley, Paul Steven; Kruglyak, V.V.; Barman, A.; Ladak, S.; Hicken, R.J.; Scott, J.; Rahman, M. (American Institute of Physics, 2005)
    It is shown that a coplanar stripline structure containing indium tin oxide windows can be used to perform optical ferromagnetic resonance measurements on a sample grown on an opaque substrate, using a pulsed magnetic field ...
  • Use of the Faraday optical transformer for ultrafast magnetization reversal of nanomagnets 

    Kruglyak, V.V.; Portnoi, M.E.; Hicken, R.J. (SPIE - Society of Photo-Optical Instrumentation Engineers, 2007)
    We propose a new strategy for ultrafast magnetization reversal of nanomagnets. Due to the Inverse Faraday Effect, circularly polarized optical pulses induce a pulsed magnetic flux in materials with large magneto-optical ...
  • The UV-Excess survey of the northern Galactic plane 

    Groot, Paul J.; Verbeek, Kars; Greimel, Robert; Irwin, Mike; González-Solares, Eduardo; Gänsicke, Boris T.; de Groot, Eelco; Drew, Janet; Augusteijn, Thomas; Aungwerojwit, Amornrat; Barlow, Mike; Barros, Susana; Van Den Besselaar, Else J. M.; Casares, Jorge; Corradi, Romano; Corral-Santana, Jesús M.; Deacon, Niall; van Ham, Wilbert; Hu, Haili; Heber, Uli; Jonker, Peter G.; King, Rob; Knigge, Christian; Mampaso, Antonio; Marsh, Tom R.; Morales-Rueda, Luisa; Napiwotzki, Ralf; Naylor, Tim; Nelemans, Gijs; Oosting, Tim; Pyrzas, Stylianos; Pretorius, Magaretha; Rodríguez-Gil, Pablo; Roelofs, Gijs H. A.; Sale, Stuart; Schellart, Pim; Steeghs, Danny; Szyszka, Cezary; Unruh, Yvonne; Walton, Nicholas A.; Weston, Simon; Witham, Andrew; Woudt, Patrick; Zijlstra, Albert (Oxford University Press for Royal Astronomical Society, 2009)
    The UV-Excess survey of the northern Galactic plane images a 10° × 185° wide band, centred on the Galactic equator using the 2.5-m Isaac Newton Telescope in four bands (I5875) down to ~21-22 mag ( in I5875). The setup and ...
  • Variable-phase method and Levinson's theorem in two dimensions: Application to a screened Coulomb potential 

    Portnoi, M.E.; Galbraith, I. (Elsevier, 1997)
    The variable-phase approach is applied to scattering and bound states in an attractive Coulomb potential, statically screened by a two-dimensional (2D) electron gas. A 2D formulation of Levinson's theorem is used for ...
  • Voltage dependent director of a homeotropic negative liquid crystal cell 

    Ruan, Lizhen; Yang, Fuzi; Sambles, J. Roy (American Institute of Physics, 2008)
    Thin layers of obliquely (60° to normal) thermally evaporated SiOx lead to homeotropic alignment of a nematic liquid crystal (LC) having negative dielectric anisotropy. Under application of an ac voltage the director, as ...
  • Water vapour in the atmosphere of a transiting extrasolar planet 

    Tinetti, Giovanna; Vidal-Madjar, A.; Liang, Mao-Chang; Beaulieu, Jean-Philippe; Yung, Yuk; Carey, Sean; Barber, Robert J.; Tennyson, Jonathan; Ribas, Ignasi; Allard, Nicole; Ballester, G.; Sing, David K.; Selsis, Frank (Nature Publishing Group, 2007)
    Water is predicted to be among the most abundant (if not the most abundant) molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets ('hot Jupiters'). Several attempts have been made to ...
  • Waveguide arrays as plasmonic metamaterials: transmission below cutoff 

    Hibbins, Alastair P.; Lockyear, Matthew J.; Hooper, Ian R.; Sambles, J. Roy (American Physical Society, 2006)
    Since the work of Ebbesen et al. [Nature (London) 391, 667 (1998)], there has been immense interest in the optical properties of subwavelength holes in metal layers. While the enhanced transmission observed is generally ...
  • Zero-energy states in graphene quantum dots and rings 

    Downing, C.A.; Stone, D.A.; Portnoi, M.E. (2011)
    We present exact analytical zero-energy solutions for a class of smooth-decaying potentials, showing that the full confinement of charge carriers in electrostatic potentials in graphene quantum dots and rings is indeed ...