ELECTROMAGNETIC ABSORPTION IN AN ELECTRON-HOLE DOUBLE-LAYER SYSTEM INA MAGNETIC-FIELD

The high-frequency magnetoconductivity for a double-layer electron-hol e system is calculated at finite temperature. The formalism rests on t he temperature Green's function and Kubo's formula for conductivity. I t is found that at frequencies higher than the cyclotron frequencies o f electrons and holes, the frequency-dependent electromagnetic absorpt ion exhibits oscillatory behaviour. The maxima in the absorption coeff icient correspond to a situation where the photon energy is approximat ely the sum of the energies of the electron pair and the hole pair whi ch are simultaneously excited by the radiation field.