A model based on the response of the ions to the presence of a single test particle for the ion distribution near a charged surface was developed. It was found that the model can produce the exact density profile in the limits of weak and strong coupling, which correspond to zero and infinite values of the dimensionless coupling parameter. The model also provided an elementary theoretical framework for studying ion correlation effects near charged objects. It was concluded that for large values of the coupling parameter, the model can predict a crossover from exponential to algebraic decay at large distance from the charged plate.
Bibliographical noteFunding Information:
We wish to thank Andre Moreira and Roland Netz for providing us with their simulation data. We thank Boris Shklovskii for helpful comments and thank Nir Ben-Tal, Daniel Harries, Dalia Fishelov, and Emir Haliva for useful advice regarding the numerical solution of the partial differential equation. Support from the Israel Science Foundation (ISF) under Grant No. 210/02 and the U.S.-Israel Binational Foundation (BSF) under Grant No. 287/02 is gratefully acknowledged.