POLARON ENERGY AND EFFECTIVE MASS IN A QUANTUM-WELL

The polaron energy and effective mass are calculated for an electron in a quantum-well structure in the absence of a magnetic field. Interaction with interface optical-phonon modes and confined slab LO-phonon modes are incorporated in the calculation, and a comparison is made with the results in which the phonons are assumed to be three dimensional (3D). Three different confining potentials are investigated: (1) a parabolic well, (2) an infinite-barrier quantum well, and (3) the finite-barrier quantum well. A detailed study has been made of the importance of incorporating different energy levels. Our approach is able to recover the 2D and the 3D result for the case of a parabolic well and the infinite-high-barrier quantum-well model. For the quantum well with finite barrier height, we propose an approximation that leads to the correct limits. © 1990 The American Physical Society.