Casimir force between semiconductor and metal and compensation of surface charges

Abstract

Measurement of the Casimir forces is restricted by well-conducting materials, for which the residual electrostatic force can be compensated. For semiconductors and dielectrics, it is considered as impossible due to the effect of surface charging. In this paper, the possibility to compensate for the electrostatic interaction between a metal and poor conducting material is analyzed. It is shown that the electrostatic force can be compensated at certain conditions. For semiconductors, it is possible if the sign of the surface charges is opposite to that of the main carriers. Otherwise, the compensating potential is too large and distance dependent. For dielectrics, the surface charges can be compensated for a thin dielectric film deposited on a good conductor. These findings open the way to investigate the Casimir interaction for poor-conducting materials.