Frictional drag between quantum wells mediated by fluctuating electromagnetic field

We use the theory of the fluctuating electromagnetic field to calculate the frictional drag between nearby two-and three dimensional electron systems. The frictional drag results from coupling via a fluctuating electromagnetic field, and can be considered as the dissipative part of the van der Waals interaction. In comparison with other similar calculations for semiconductor two-dimensional system we include retardation effects. We consider the dependence of the frictional drag force on the temperature T , electron density and separation d. We find, that retardation effects become dominating factor for high electron densities, corresponding thing metallic film , and suggest a new experiment to test the theory. The relation between friction and heat transfer is also briefly commented on. 1 Introduction A great deal of attention has been recently devoted to double layer systems in which two parallel quasi-two-dimensional (2D) subsystems (electron or hole gases) are separated by a potential barrier thick enough to prevent particles 1