Dielectric screening by 2D substrates

Model dielectric function for 2D semiconductors including substrate screening

Dielectric screening of excitons in 2D semiconductors is known to be a highly non-local effect, which in reciprocal space translates to a strong dependence on momentum transfer q. We present an analytical model dielectric function, including the full non-linear q-dependency, which may be used as an alternative to more numerically taxing ab initio screening functions. By verifying the good agree...

Reflectivity of Reflectarrays Based on Dielectric Substrates

Problem statement: Reflectarrays provide a low cost and low profile solution for antennas required for high gain applications but their use is restricted in some applications due to the narrow bandwidth and high loss performance. These performance limitations can be attributed to different sources of reflectivity of the reflectarrays. This work provides a thorough investigation on the reflectiv...

Physical optics modeling of 2D dielectric lenses.

We propose an advanced physical optics formulation for the accurate modeling of dielectric lenses used in quasi-optical systems of millimeter, submillimeter, and infrared wave applications. For comparison, we obtain an exact full-wave solution of a two-dimensional lens problem and use it as a benchmark for testing and validation of asymptotic models being considered.

Cancer cell migration on 2D deformable substrates

Dielectric screening in doped Fullerides

For conventional superconductors the electron-electron interaction is strongly reduced by retardation effects, making the formation of Cooper pairs possible. In the alkali-doped Fullerides, however, there are no strong retardation effects. But dielectric screening can reduce the electron-electron interaction sufficiently, if we assume that the random-phase approximation (RPA) is valid. It is no...