Stopping Power for Slow Ions in an Electron Liquid: Time-Dependent Density-Functional Theory

Chang Sub Kim

Department of Physics and Institute for Condensed Matter Theory, Chonnam National University, Gwangju 500-757, Korea

Based on the time-dependent density-functional theory, we have derived a formula for the stopping power of an electron liquid for slow ions, which is exact in the limit of low projectile velocities. If dynamical correlation between electrons is not taken into account, the formula is reduced to the conventional one as obtained by using noninteracting Kohn-Sham electrons in a central potential. The correlation effect, specifically the excitonic one in the electron-hole pair excitations, however, is found to be very important and considerably enhances the stopping power for highly charged ions, bringing our theory into better agreement with experiment than the conventional one.

This work has been done in collaboration with V. U. Nazarov (ICMT, CNU). We acknowledge the support by the Korea Research Foundation through Grant No. KRF-2003-015-C00214.