各向异性抛物势对量子点中强耦合极化子激发态的影响

Effects of an Anisotropic Parabolic Potential on the Excited State Energy of a Strong-Coupling Polaron in a Quantum Dot

在各向异性抛物势限制下,采用Huybrechts线性组合算符和Lee-Low-Pines(LLP)幺正变换方法研究了量子点中强耦合极化子激发态的性质.导出了极化子第一激发态振动频率和第一激发态能量随电子-声子耦合强度和各向异性抛物势在量子点三个方向上的有效受限长度的变化关系.数值结果表明:第一激发态振动频率和第一激发态能量是电子-声子耦合强度的增函数且它们均随有效受限长度的增加而迅速减少,表现出量子点新奇的量子尺寸限制效应.

Under the influence of an anisotropic parabolic potential （APP）, we investigate the properties of excited state of a strong-coupling polaron in a quantum dot （QD） by using the Huybrechts＇ linear combination operation and the Lee-Low-Pines （LLP） unitary transformation methods. The relations of the vibrational frequency and the energy of the first excited state with the electron-phonon coupling strength and the effective confinement lengths are derived. Numerical results have showed that the vibrational frequency and the energy of the first excited state are increasing functions of the eleetron-phonon coupling strength and they all will decrease rapidly with increasing the effective confinement lengths which are showing the novel quantum size confining effect of the quantum dot.