Polarons in semiconductor quantum structures
Faculty of Sciences. Physics
Molecular nanowires and other quantum objects
NATO Advanced Research Workshop on Molecular Nanowires and Other Quantum, Objects, SEP 07-09, 2003, Bled, SLOVENIA
, p. 139-150
University of Antwerp
In this presentation three recent contributions to the theory of continuum (or "Frohlich"-) polarons are reviewed. (i) Using a generalization of the Jensen-Feymnan variational principle within the path-integral formalism for identical particles, the ground-state energy of a confined N-polaron system is studied as a function of N and of the electron-phonon coupling strength. (ii) A theoretical investigation of the optical properties of stacked quantum dots is presented, which is based on the non-adiabatic approach. (iii) Cyclotron-resonance (CR) spectra of a gas of interacting polarons in a GaAs/AlAs quantum well are theoretically investigated taking into account the magnetoplasmon-phonon mixing and the band nonparabolicity. The theory explains that, for a high-density polaron gas, anticrossing of the CR spectra occurs near the GaAs TO-phonon frequency rather than near the GaAs LO-frequency in a good agreement with experimental data.