声子和磁场对量子环中极化子性质的影响

Influence of phonon and magnetic field on property of polaron in quantum ring

采用求解能量本征方程、幺正变换和变分相结合的方法,研究声子和磁场对量子环中极化子性质的影响.对KBr量子环的数值计算表明,电子或极化子的基态能量随量子环频率(或平均半径)的增大而增大,极化子基态能移随量子环频率的增大(或平均半径的减小)而减小,极化子中的平均声子数随量子环频率的增大(或平均半径的减小)而增大.当有垂直磁场时,极化子基态能量和基态能移与外磁场及电子转动状态有关.随着磁场强度的增大,基态能量出现简并且呈现非周期性振荡;能移随磁场强度的增大(或转动量子数绝对值的减小)而减小.

The influence of phonon and megnetic field on property of polaron in quantum ring was studied by solving precisely the energy eigen-equation,unitary transformation and variational method.The numerical calculation for KBr quantum ring showed that the ground state energy of electron or polaron increases with increasing frequency（or the averaging radius） of the quantum ring,the polaron energy shift decreases with increasing frequency（or decreasing averaging radius） of the quantum ring,and the mean phonon number increases with increasing frequency（or decreasing averaging radius） of the quantum ring.When a perpendicular magnetic field is present,the energy levels of the polaron may cross,the ground state changes from the state with m = 0 to that with m =-1,-2,-3,…,and the ground state energy makes non-periodical oscillation with increasing magnetic field strength;the polaron energy shift decreases with increasing magnetic field strength（or absolute value of quantum number ︱m︱）.