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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:16 |
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Conference: Bucharest University Faculty of Physics 2012 Meeting
Section: Solid State Physics and Materials Science
Title:
Ballistic electron propagation in a composite metamaterial
Authors:
Ana DUMITRIU, Daniela DRAGOMAN
Affiliation:
University of Bucharest, Physics Dept., P.O. Box MG-11, 077125 Bucharest, Romania
E-mail
dumitriu.ana.elena@gmail.com, danieladragoman@yahoo.com
Keywords:
ballistic transport, metamaterials, quantum-optical analogies
Abstract:
The analogies between propagation of monochromatic electromagnetic waves and the time-independent transport of Schrödinger electrons suggest that quantum barriers in layers with a negative effective mass play the role of optical metamaterials in which both electrical permittivity and magnetic permeability are negative. Here, we show that ballistic charge carriers can propagate with significant transmission probability through a periodic structure that acts as a composite metamaterials for electrons, formed from layers that are either barriers for electrons or that have a negative effective mass. As through a similar structure in optics, electrons can pass through such a composite metamaterial even in energy intervals in which the wavenumber takes imaginary values in both layers that form the period. In addition, we have calculated the phase and traversal times through the periodic structure, which characterize the propagation of narrow energy range pulses and monoenergetic electron waves, respectively. The energy dependence of these parameters are expected to differ due to their different meaning. However, both are comparable to the traversal time in the absence of the periodic composite metamaterial in most of the considered energy range, the phase time showing (at least for the simulation parameters used in this work), unlike the traversal time, an accelerating effect of the composite structure.
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