中国物理B ›› 1999, Vol. 8 ›› Issue (5): 361-367.doi: 10.1088/1004-423X/8/5/007
黄永畅1, 刘亚1, 刘自信2, 贾天卿3
Liu Zi-xin (刘自信)a, Huang Yong-chang (黄永畅)b, Liu Ya (刘亚)b, Jia Tian-qing (贾天卿)c
摘要: We have proposed the Hamiltonian of the single or double polaron bound to a helium-type donor impurity in semiconductor quantum wells (QWs) in the case of positively charged donor center and neutral donor center. The couplings of an electron with various phonon modes are considered; in particular, the interaction of the impurity with the various phonon modes is included. We have calculated the binding energy of a bound polaron in Al(xl)Ga1-(xl)As/GaAs/Al(xr)Ga1-(xr) As symmetric and asymmetric QWs. The results are obtained as a function of barrier height (or equivalently of Al concent ration x), well width, and the position of impurity in the QWs. Our numerical calculations show clearly that for a thin well the cumulative effects of the electron-phonon coupling and the impurity-phonon coupling can contribute appreciably to the donor binding energy. The enhancement of polaronic effect is also found in the case of ionized donor.
中图分类号: (Polarons and electron-phonon interactions)