Coulomb drag in intermediate magnetic fields

Abstract

We theoretically investigated the Coulomb drag effect in coupled two-dimensional electron gases in a wide interval of magnetic field and temperature $1/\ensuremath{\tau}\ensuremath{\ll}{\ensuremath{\omega}}_{c}\ensuremath{\ll}{E}_{F}/\ensuremath{\Elzxh}, T\ensuremath{\ll}{E}_{F}, \ensuremath{\tau}$ being the intralayer scattering time and ${\ensuremath{\omega}}_{c}$ the cyclotron frequency. We show that quantization of the electron spectrum leads to rich parametric dependences of the drag transresistance on the temperature and magnetic field. This is in contrast to usual resistance. Small energy scales are found to cut typical excitation energies to values lower than temperature. This may lead to a linear temperature dependence of the transresistance even in a relatively weak magnetic field, and can explain some recent experimental data. We present a mechanism of Coulomb drag when the current in the active layer causes a magnetoplasmon wind and the magnetoplasmons are absorbed by the electrons of the passive layer providing a momentum transfer. We derived general relations that describe the drag as a result of resonant tunneling of magnetoplasmons.