声子之间相互作用对弱耦合量子点中极化子内声子平均数的影响

Influence of Interaction Between Phonons on Mean Number of Polaron Phonons in Weak-coupling Quantum Dot

采用线性组合算符和幺正变换方法,研究了量子点中弱耦合极化子的性质。在考虑声子之间相互作用时,讨论了极化子的基态能量随量子点受限长度和平均声子数的变化关系。数值计算结果表明:极化子的基态能量和平均声子数都随量子点受限长度的增加而减少,平均声子数随基态能量的增加而增加。在基态能量相同时,考虑声子之间相互作用时的平均声子数比不考虑声子相互作用时的平均声子数要小一些,即声子之间的相互作用对量子点中平均声子数影响不能忽略。

The properties of weak-coupling polaron are studied by using the linear combination operator and the unitary transformation methods in quantum dot. Considering the interaction between phonons of different wave vector in the recoil process, the ground state energy of polaron as a function of the confinement length of quantum dot and the mean number of phonons are discussed. Numerical calculation results showed that the ground state energy of polaron and the mean number of phonons decreased with increase of the confinement length of the quantum dot, and the mean number of phonons increased with the increase of the ground state energy of the quantum dot. When the ground state energy was held constant, the mean number of phones was less when the interaction between phones was considered than when the interaction was not considered. This showed that the influence of interaction between phonons on the mean number of phonons cannot be ignored.