69,783 research outputs found
Measurement of surface potential decay of corona-charged polymer films using the pulsed electroacoustic method
In this paper, the pulsed electroacoustic (PEA) technique that allows the determination of space charge in a dielectric material has been used to monitor the electrical potential decay of corona-charged polyethylene films of different thicknesses. To prevent possible disturbance on the surface charge during the PEA measurements, two thin polyethylene films were placed on both sides of the corona-charged sample. Charge profiles measured at different times were used to calculate the potential across the sample. The obtained potential decay was compared with the potential measured using the conventional method. A good agreement has been obtained. More importantly, the charge profile obtained using the PEA technique indicates that bipolar charge injection has taken place
Intense terahertz laser fields on a two-dimensional electron gas with Rashba spin-orbit coupling
The spin-dependent density of states and the density of spin polarization of
an InAs-based two-dimensional electron gas with the Rashba spin-orbit coupling
under an intense terahertz laser field are investigated by utilizing the
Floquet states to solve the time-dependent Schr\"odinger equation.
It is found that both densities are strongly affected by the terahertz laser
field. Especially a terahertz magnetic moment perpendicular to the external
terahertz laser field in the electron gas is induced. This effect can be used
to convert terahertz electric signals into terahertz magnetic ones efficiently.Comment: 3 pages, 3 figures, a typo in Fig. 3(b) is correcte
Thermal rectification in asymmetric U-shaped graphene flakes
In this paper, we study the thermal rectification in asymmetric U-shaped
graphene flakes by using nonequilibrium molecular dynamics simulations. The
graphene flakes are composed by a beam and two arms. It is found that the heat
flux runs preferentially from the wide arm to the narrow arm which indicates a
strong rectification effect. The dependence of the rectification ratio upon the
heat flux, the length and the width of the beam, the length and width of the
two arms are studied. The result suggests a possible route to manage heat
dissipation in U-shaped graphene based nanoelectronic devices.Comment: 3 pages, 4 figure
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