量子线中强耦合极化子的温度效应

采用Tokuda改进的线性组合算符法和有效质量下的变分法,研究在抛物势作用下,同时考虑电子与LO声子相互作用时,温度对量子线中强耦合极化子特性的影响。对RbCl晶体所作的数值计算结果表明,量子线中强耦合极化子的基态能量、平均数和光学声子平均数均随温度的升高而增加。

Temperature Effects of Strong Coupling Polaron in Quantum Wire

Recently, many theoretical and experimental studies of the electromagnetic and optical properties of low-dimensional semiconducting quantum structures have been carried out because of the intrinsic physical interest of these structures as their wide ranging, possible applications in the future. Quantum wires, in particular, play an important role in microelectronic and optoelectronic devices. Since a quantum wire is a one-dimensional structure with the electron motion confined in two-directions, quantum effects are more apparent than that in a two-dimensional quantum structure. In addition, the physical properties of quantum wires may be controlled by applied external electric and magnetic fields. External fields are therefore of great importance in studies on the properties of quantum wires.Following the recent proposal by Sakaki of a quantum wire that can be produced using modern growth techniques, a great deal of theoretical and experimental effort has been directed toward these structures. Li et al. studied the effects of the parabolic potential and confined phonons on a free polaron in a parabolic quantum wire. Yeung et al. investigated the cyclotron resonance of a strong parabolic potential and weak electron-LO-phonon coupling. Chuu et al. have investigated the energies of the ground state and the excited state in cylindrical quantum wires using Pekar alternative approach and perturbation-variational approach. Krishna et al. studied the effects of electron-phonon interaction on the ground and excited state energies of an electron in a polar quantum strip by using a variational method. The properties of polaron and megnetopolaron in cylindrical quantum wires, rectangular quantum wires and parabolic quantum wires have been studied by the method of linear-combination operator and unitary transformation by one of the present authors and co-worker.In this paper, we studied some properties of strong-coupling polarons in a parabolic quantum wires under a finite temperature. The system ground state energy and the mean number of optical phonon are derived by using improved linear combination operators and the variational method. Numerical calculations, for the RbCl crystal as an example, are performed. The results indicate that the mean number and the ground state energy of polaron, the mean number of phonons of the strong-coupling polaron in a quantum wire increase with the increase of the temperature.