温度对抛物量子点中弱耦合束缚磁极化子的影响

采用线性组合算符和幺正变换方法研究温度对量子点中弱耦合束缚磁极化子性质的影响,导出了弱耦合束缚磁极化子的振动频率、基态能量和声子平均数随温度的变化关系。取CdTe晶体为例进行数值计算,结果表明:弱耦合束缚磁极化子的振动频率、基态能量和声子平均数随温度的升高而增大,基态能量随量子点的受限强度的增强而迅速增大。

Influence of the Temperature on the Properties of Weak-coupling Bound Magnetopolaron in a Parabolic Quantum Dot

In recent years,with the development of several experimental techniques,for example,molecular beam epitaxy and metal-organic chemical-vapour deposition,there has been of considerable interest in lowdimensional semiconductor structures such as quantum dots,quantum wells and quantum wires.There has been more and more interest in quantum dots due to novel physical property and extensive application prospects. In the past over ten years,many people studied the properties of a bound magnetopolaron in a parabolic quantum dot extensively by using many kinds of methods both theoretically and experimentally.In this paper,the influence of the temperature on the properties of weak-coupling bound magetopolaron in a parabolic(quantum) dot is studied.The vibration frequency,the ground state energy and the mean number of phonons of the weak-coupling bound magnetopolaron in a parabolic quantum dot are derived by using the linear(combination) operator and the unitary transformation method.The relations between the vibration frequency,the ground state energy and the mean number of phonons of the weak-coupling bound magnetopolaron with the temperature are discussed.Numerical calculations,for the CdTe crystal as an example,are performed and the results indicate that the vibration frequency of weak-coupling bound magnetopolaron in a quantum dot will(increase) with increasing the temperature,the mean number of phonons of weak-coupling bound magnetopolaron will increase with increasing the temperature and will increase with decreasing the vibration frequency of magnetopolaron.The ground state energy of the weak-coupling bound magnetopolaron will increase strongly with increasing the confinement strength of the quantum dot,and at the same position(same value of ω₀),the higher temperature,the higher is the value of ground state energy.This is because crystal will be polarized more easily,LO-phonons will become manifold with the increasing of temperature.In this case,the interaction of electron and more LO-phonons makes the ground state energy and the mean number of phonons of the weak-coupling bound magnetopolarn increase in a quantum dot.