Calculation of reduction factors for the Γ8-(e+t) Jahn-Teller case with applications to acceptor defects in semiconductors

The reduction factors of the general one-mode Gamma 8 -(e+t) Jahn-Teller (JT) case are calculated throughout the whole coupling range. For small JT coupling parameters the authors use standard matrix diagonalisation procedures combined with a group theoretical projection technique. The application of a unitary transformation method diagonalises the Hamiltonian exactly for infinite couplings. The resulting vibronic Glauber ground states are used for the reduction factor calculation at high coupling values. A combination with perturbational methods extends the validity of the approach to the whole range of coupling strengths. They apply the method to the case of acceptor defects in semiconductors within a one-mode approximation of the defect Hamiltonian. Results for the reduction of the acceptor deformation potential constants are given for the systems Si(In), Si(B) and GaAs(Mn).