University proceedings. Volga region. Physical and mathematical sciences, 2013 Issue 3,Pages 223–232(Mi ivpnz405)
Physics
The peculiarities of the impurity band in the quantum wire formed by a regular chain of $D^0$-centers with resonant states in the external magnetic field
Abstract:Background. Semiconductor quantum wire with impurity band are promising in terms of creating new sources of stimulated emission on the impurity transitions, as well as infrared emission photodetectors with controlled sensitivity on their basis. The aim of this work is a theoretical study of the influence of the external magnetic field on the width of the impurity band formed by a regular chain of $D^0$ centers with resonant electron states in the quantum wire. Materials and methods. The curves of the impurity band width dependency on the external magnetic field magnitude and the period of a regular chain of $D^0$centers are plotted for the case of an InSb quantum wire. Dispersion equations defining the boundaries of the impurity band in a quantum wire in the presence of an external longitudinal magnetic field relative to the axis of a quantum wire are obtained in the framework of a generalized version of the Kronig – Penney model by the zero-radius potential method. Results. It is shown that with the increasing magnitude of the external magnetic field the width of the impurity band with resonant states decreases due to the decrease of the degree of the single-site wave functions overlap. There is sufficiently high sensitivity of the impurity band width formed by a regular chain of $D^0$centers with resonant states of the impurity electron in a quantum wire to dissipative tunneling parameters: increasing temperature and phonon mode frequency causes the increase of the impurity band width due to the increased dissipative tunneling probability, and increasing medium coupling constant induces the reduction of the impurity band width due to the blocking of the tunneling decay. Conclusions. The possibility of effective control over the impurity band width formed by a regular chain of $D^0$centers with resonance states of the bound electron by varying the external magnetic field magnitude and dissipative tunneling parameters was revealed.
Keywords:quantum wire, impurity band with resonant electron states, magnetic field, dissipative tunneling, a regular chain of $D^0$ centers.