电场对抛物量子点中电子基态跃迁速率的影响

在外电场的作用下,同时抛物量子点中电子-声子强耦合的条件下,由于电子-声子的相互作用和外界温度的影响,使电子在基态吸收一个声子的能量跃迁到激发态。采用Pekar变分方法,讨论电子的基态能量、外电场、量子点的受限长度、电子-声子耦合强度和外界温度对电子跃迁速率的影响。结果表明,外界温度对电子跃迁速率的影响起主导作用,在确定的温度下,电子的基态能量越大跃迁速率越小。同时,电子跃迁速率随着电子-声子耦合强度的增加而变大,随着外电场、量子点的受限长度的增大,电子跃迁速率先减小后变大。

The Influence of Electric Field on the Transition Rate of Electron in a Parabolic Quantum Dot

The ground-state energy of electron was obtained with strong electron-LO-phonon coupling by using a variational method of the Pekar type in a parabolic quantum dot(QD).Quantum transition is occurred in the quantum system due to the electron-phonon interaction and the influence of temperature.That is the electron transition from the ground-state to the first-excited state after absorbing a LO-phonon.Numerical calculations were performed and the results illustrate the relations of the transition rate of the electron with the ground-state energy,the electric field strength,the temperature,the electron-LO-phonon coupling strength and the confinement length of the quantum dot.