Browsing by Subject "Screening effects"

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    Magnetic and electric Aharonov-Bohm effects in nanostructures
    (Elsevier BV, 1996) Kulik, I. O.
    The paper reviews and extends the magnetic Aharonov-Bohm effect (persistent current, resistance oscillation) in normal-metal rings including spin-independent and spin-dependent hopping, Zeeman splitting, magnetic textures and wheels, ring rotation and weak coupling, as well as the electric Aharonov-Bohm effect ("persistent charge") in small metallic contacts. We then discuss dynamical screening effects in a surface charge in a metal. Energy dissipation due to motion of the surface charge has a singularity at the velocity of motion equal to the phonon propagation velocity. Surface image of an external charge inside the metal is strongly distorted at the velocity of motion larger than the Fermi velocity.
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    Phonon confinement and screening effects on the polaron energy in quantum wires
    (Institute of Physics Publishing Ltd., 1995) Tanatar, Bilal; Guven, K.
    We study the contribution of confined phonons to the polaron energy in quantum-well wires. We use a dispersionless, macroscopic continuum model to describe the phonon confinement in quantum wires of square cross section. The polaron energy is calculated variationally incorporating the dynamic screening effects. We find that the confined phonon contribution to the polaron energy is comparable to that of bulk phonons in the density range N = 104-107 cm-1. Screening effects within the random-phase approximation significantly reduce the electron-confined phonon interaction, whereas the correlation effects tend to oppose this trend.