arXiv subjects

Wenping Cui

Publications and source records attributed to Wenping Cui.

21 records · Page 2Linked to original sources

arXiv2013

Topological Effect of Surface Plasmon Excitation in Gapped Isotropic Topological Insulator Nanowires

We present a theoretical investigation of the surface plasmon (SP) at the interface between topologically non-trivial cylindrical core and topological-trivial surrounding material, from the axion electrodynamics and modified constitutive relations. We find that the topological effect always leads to a red-shift of SP energy, while the energy red-shift decreases monotonically as core diameter decreases. A qualitative picture based on classical perturbation theory is given to explain these phenomena, from which we also infer that in order to enhance the shift, the difference between the inverse of dielectric constants of two materials shall be increased. We also find that the surrounding magnetic environment suppresses the topological effect. All these features can be well described by a simple ansatz surface wave, which is in good agreement with full electromagnetic eigenmodes. In addition, bulk plasmon energy at ω_{P}=17.5\pm0.2eV for semiconducting Bi2Se3 nanoparticle is observed from high-resolution Electron Energy Loss Spectrum Image measurements.

cond-mat.mes-hall↗

arXiv2013

Near-Field Optical Effect of a Core-Shell Nanostructure In Proximity to a Flat Surface

We provide an analytical solution to study the near field optical effect of a core-shell nanostructure in proximity to a flat surface, within quasi-static approximation. The distribution of electrostatic potential and field enhancement in this complex geometry are obtained by solving a set of linear equations. This analytical result can be applied to a wide range of systems associated with near field optics and surface plasmon polaritons. As an illustration of the power of this technique, we study the field attenuation effect of oxidized shell in a silver tip in near field scanning microscope. The thickness of oxidized layer can be monitored by measuring the light intensity. In addition, we propose a novel method to detect local temperature with spatial resolution down to nm scale, based on a Ag-Au core-shell structure.

cond-mat.mes-hall↗

arXiv2013

Transient Accelerating Scalar Models with Exponential Potential

We study a known class of scalar dark energy models in which the potential is of exponential type and the current accelerating era is transient. We find that, although a decelerating era will return in future, however, when extrapolating the model back to the earlier stages ($z \gtrsim 4$), the scalar dark energy becomes dominant over the matter. So these models do not have the desired tracking behavior, and the predicted transient period of acceleration can not be adopted into the standard scenario of Big Bang cosmology. When couplings between the scalar field and the matter are introduced, the models still has the problem, only the time of deceleration return will be varied. To achieve re-deceleration, one has to turn to alternative models that are consistent with the standard Big Bang scenario.

astro-ph.CO↗