Channeling phenomena of He,Ne,Ar and Kr ions at energy(200–5000 eV)in single-wall carbon nanotubes(SWCNTs)are investigated by molecular dynamics simulation with analytical potentials.The critical angles for the particles to be channeled in an SWCNT are analyzed.In the incident energy range of 200–5000 eV,it is found that the ion energy dependence of the critical angle obeys an improved Lindhard equation which is closely related to the ratio of nuclear charge number to atomic mass Z/M.The critical angle for different types of ions channeling in SWCNTs is determined by both the atomic nuclear charge and mass.
LI YongZHENG Li-PingZHANG WeiXU Zi-JianREN Cui-LanHUAI PingZHU Zhi-Yuan
In this paper,we present a theoretical study on excitonic absorption spectra of one-dimensional semiconductor quantum wires.The carrier-carrier scattering is treated by the second Bom approximation in the Markovian limit.The absorption spectra of different carrier densities and temperatures are discussed.The excitonic absorption peak position and width show complicated dependence on carrier density and temperature,indicating the importance of carrier-carrier scattering.The behavior can be understood by the cooperative effects of exchange self-energy and Coulomb correlation due to carrier-carrier scattering.
