One-dimensional electron localization in semiconductors coupled to electromagnetic cavities

The electrical conductivity of one-dimensional (1D) disordered solids exhibits exponential decay with respect to their length, a well-known manifestation of the localization phenomenon. In this study, we investigate alterations in the conductivity resulting from the insertion of 1D semiconductors into single-mode electromagnetic cavities, focusing specifically on the regime of nondegenerate doping. Our approach employs the Green's function technique adapted for the nonperturbative consideration of cavity-excited states. This encompasses coherent electron-cavity effects, such as electron motion within the zero-point fluctuating field, as well as incoherent photon emission processes during tunneling. The energy spectrum of electron transmission across the cavity develops Fano-type resonances linked to virtual photon emission, passage along a resonant level, and photon reabsorption. The quality factor of the Fano resonance depends on whether the intermediate state is coupled to the leads, reaching its maximum when this state is deeply localized within the disorder potential. Coupling to the cavity also raises the energies of shallow bound states, bringing them close to the conduction band bottom. This effect results in an enhancement of the conductance at low temperatures.