声子和温度对球型量子点中极化子性质的影响

The influence of phonon and temperature on properties of polaron in spherical quantum dot

采用求解能量本征方程、幺正变换及变分相结合的方法,研究声子和温度对球型量子点中极化子性质的影响.数值计算表明,声子效应导致极化子的基态能量低于电子能量,且极化子基态能量随电子-声子耦合强度的增大而降低.数值计算还表明,当温度较低,使得电子热运动能量小于声子能量时,声子不会被激发,极化子的基态能量不随温度的变化而变化;在温度较高,使得电子热运动能量大于声子能量时,电子和晶格热运动加剧,更多的声子被激发.极化子的基态能量随温度的升高而增大.

The influence of phonon and temperature on properties of polaron in spherical quantum dot is studied by solving precisely the eigen-energy equation ,LLP unitary transformation and variation method . Numerical calculations for GaAs spherical quantum dot indicate that the phonon effect leads to ground state energy of polaron lower than electronic ground state energy, and the ground state energy of polaron decreases with increasing coupling strength between electron and phonon. Numerical calculations also show that few phonons are excited at low temperature, the ground state energy of polaron is const, while phonons can be excited at higher temperature, the ground state energy of polaron increase with rising temperature.