自旋对半导体量子点中强耦合磁极化子性质的影响

Influence of spin on the properties of a strong coupling magnetopolarons in semiconductor quantum dots

在考虑电子自旋的情况下,应用么正变换和线性组合算符法研究了半导体量子点中强耦合磁极化子振动频率、基态能和基态结合能的性质。数值计算结果表明:电子自旋使磁极化子基态结合能分裂为二Eb(1/2)和Eb(-1/2),其间距与外磁场B成线性关系。当回旋共振频率小于和大于10倍声子振动频率时,Eb(1/2)随B的增大分别缓慢和迅速减小。当回旋共振频率小于和大于20倍声子振动频率时,Eb(-1/2)随B的增大分别迅速和缓慢增大。当回旋共振频率为440倍声子振动频率时,Eb(-1/2)取最大值为44倍声子能量。之后Eb(-1/2)随B的增大逐渐减小。随着磁场的加强,电子自旋影响增大。当回旋共振频率超过声子振动频率的5.97和820倍时,电子自旋能量已分别大于电子所受束缚势和电子与LO声手之间的诱生势。

Considering the electron spin, the vibration frequency, ground state energy and ground state binding energy of a strong coupling magnetopolaron in semiconductor quantum dots were derived by using the linear combination operator and perturbation method. Numerical calculation show that the electron spin divides the ground state binding energy into two Eb （-1/2） and Eb （-1/2） ,and the energy spacing has linear relation with outside magnetic field B. When cyclotron resonance frequency（CRF） 10 times smaller and larger than phonon vibration frequency（PVF）,Eb （-1/2） respectively slowly and rapidly reduced with B increasing. When CRF; large than larger than; partly respectiver 20 times smaller and large than PVF,Eb（-1/2）partly rapidly and slowly increases with B increasing. When CRF 440 times larger than PVF,Eb（-1/2）＇s maximum value is 44 times larger than phonon energy. Then Eb （-1/2） slowly reduces with B increasing. The spin influence will increase with B increasing. When CRF 5.97 times and 820 times larger than PVF,the electron spin energy has already larger than the binding potential and the induced potential caused by the interaction between the electron and LO phonons.