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Browsing by Author "Hewageegana, P."

Browsing by Author "Hewageegana, P."

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  • Absolute phase effect in ultrafast optical responses of metal nanostructures 
    Stockman, M.I.; Hewageegana, P. (APPLIED PHYSICS A: MATERIALS SCIENCE & PROCESSING, 2007)
    We predict that nonlinear ultrafast electron photoemission by strong optical fields and, potentially, other nonlinear optical responses of metal nanostructures significantly depend on the absolute (carrier?envelope) phase ...
  • Circularly-polarized-pulse-driven ultrafast optical currents in monolayer hexagonal Boron Nitride (h-BN) 
    Hewageegana, P.; Apalkov, V. (Solid State Communications, 2022)
    We predict the fundamentally fastest, ultrafast optical currents in monolayer hexagonal Boron Nitride (h-BN) by a circularly-polarized single-oscillation optical pulse. The femtosecond currents in gapped graphene and ...
  • Circularly-polarized-pulse-driven ultrafast optical currents in monolayer hexagonal Boron Nitride (h-BN) 
    Hewageegana, P.; Apalkov, V. (Solid State Communications, 2022)
    We predict the fundamentally fastest, ultrafast optical currents in monolayer hexagonal Boron Nitride (h-BN) by a circularly-polarized single-oscillation optical pulse. The femtosecond currents in gapped graphene and ...
  • Electron localization in graphene quantum dots 
    Hewageegana, P.; Apalkov, V. (Physical Review B, 2008)
    We study theoretically a localized state of an electron in a graphene quantum dot with a sharp boundary. Due to Klein?s tunneling, the ?relativistic? electron in graphene cannot be localized by any confinement potential. ...
  • Enhanced mid-infrared transmission through a metallic diffraction grating 
    Hewageegana, P.; Apalkov, V. (Journal of Physics: Condensed Matter, 2008)
    We study theoretically an enhancement of the intensity of mid-infrared light transmitted through a metallic diffraction grating. We show that for s-polarized light the enhancement of the transmitted light is much stronger ...
  • Expanding universe with a time-dependent cosmological constant 
    Jayawardane, S.; Katugampola, K. D. W. J.; Hewageegana, P. (4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019)
    It is possible to examine the expansion of universe with an accelerating epoch. The prophecy of an expanding universe from Einstein's Field Equations were affirmed by the perceptions of Edwin Hubble and Adam G. Reises in ...
  • Graphene Quantum Dots 
    Hewageegana, P.; Apalkov, V. (2010)
  • Investigation of temperature and density profile of brine in evaporating salt pans at Palavi in north-western Sri Lanka 
    Hewageegana, P.; Amarasekara, C.D.; Jayakody, J.R.P.; Punyasena, M.A. (2001)
    Measurements of temperature and density variations with depth in salt pans having a stable salinity gradient are presented. The density variation of brine has been correlated to the temperature variation with depth. The ...
  • Localized modes of an electron by topological insulator defect 
    Kumara, R.D.M.M.; Hewageegana, P. (Faculty of Science, University of Kelaniya, Sri Lanka, 2016)
    Topological insulators, a new class of materials discovered recently, have very unique topological properties. While the surface states are gapless and are topologically protected by the time reversal symmetry, the bulk ...
  • Nanolocalized Nonlinear Electron Photoemission under Coherent Control 
    Stockman, M.I.; Hewageegana, P. (Nano Letters, 2005)
    We theoretically show that two-photon coherent control yields electron photoemission from metal nanostructures that is localized in nanosize hot spots whose positions are controllable on a nanometer scale, in agreement ...
  • Plasmonic enhancing nanoantennas for photodetection 
    Hewageegana, P.; Stockman, M.I. (Infrared Physics & Technology, 2007)
    This paper discusses the use of plasmonic nanostructured systems as nanoantennas for photodetection. Even though semiconductors and their heterostructures have many useful properties and widely used in photodetection, their ...
  • Polarizability per Unit Length of a Nanowire including Nonlocal Effects 
    Hewageegana, P. (University of Kelaniya, 2012)
    It is well known that the electronic and optical properties of very small structures such as, nanospheres, nanowires, nanocavities and nanocylinders are very different from those of the corresponding bulk materials because ...
  • A quantum dot in topological insulator nanofilm 
    Herath, T.M.; Hewageegana, P.; Apalkov, V. (2014)
  • Quantum dot photodetectors with metallic diffraction grating: Surface plasmons and strong absorption enhancement 
    Hewageegana, P.; Apalkov, V. (Physica E: Low-dimensional Systems and Nanostructures, 2008)
    We report our theoretical study of the effect of metallic diffraction grating on the sensitivity of quantum dot photodetectors in terahertz frequency. We have found that the effect of diffraction grating is much stronger ...
  • Research in Buddhism and Physics 
    Galmangoda, Sumanapala; Hewageegana, P. (Research in Buddhism and Physics, )
    Theory of Perception According to Buddhism everything in the world is impermanent. Everything is momentary. But there is a difference of life-span of mind and matter. The life-span of consciousness is termed as mind-moment ...
  • Second harmonic generation in disordered media: Random resonators 
    Hewageegana, P.; Apalkov, V. (Physical Review B, 2008)
    We theoretically study the effect of random resonators on the conversion efficiency of fundamental mode propagating through disordered nonlinear dielectric film. Only resonators with double-resonant properties, i.e., which ...
  • Strong photoelectron emission from silver nanostructures 
    Hewageegana, P. (Journal of Science of the University of Kelaniya Sri Lanka, 2010)
    Localized optically-nonlinear photoelectron emission from metal (silver) nanostructures under two-pulse emission has been developed for relatively low energy. For two-photon emission from random metal nanostructures, it ...
  • Theoretical study of terahertz quantum well photodetectors: Effect of metallic diffraction coating 
    Hewageegana, P.; Apalkov, V. (Infrared Physics & Technology, 2008)
    The possibility of enhancement of sensitivity of quantum well photodetectors by adding metallic diffraction coating on top of the dielectric layer of photodetectors is studied. With the grating the spatial distribution of ...
  • Trapping of an electron in coupled quantum dots in graphene 
    Hewageegana, P.; Apalkov, V. (Physical Review B, 2009)
    Due to Klein?s tunneling the electronic states of a quantum dot in graphene have finite widths and an electron in quantum dot has a finite trapping time. This property introduces a special type of interdot coupling in a ...

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