Quantum-mechanical approach to the description of the interaction between microwave radiation and conducting thin films

The paper presents a quantum-mechanical analysis approach of the electromagnetic radiation interaction with the ultrathin conducting films in the frequency range of 1–200 GHz. It was shown that at film thicknesses less than 10 nanometers, the structure symmetry of the atomic conductor lattice must be taken into account, a violation of which can lead to the appearance of a band gap, which greatly differs from the crystalline material. The band gap has a strong influence on the conductivity of a thin metal film and on its electromagnetic properties. Using aluminum as an example, it is shown that in case of symmetry breaking of the face-centered crystal lattice, the band composed of the valence and the conduction bands splits with the band gap formation of 0.07 eV.