库仑势对抛物量子点量子比特消相干的影响

采用Pekar类型的变分方法，在电子与体纵光学声子强耦合的条件下，计算得出了抛物量子点中电子的基态能量和第一激发态能量及其相应的本征波函数.量子点中这样的二能级体系可以作为一个量子比特.由于声子的自发辐射，造成量子比特的消相干，讨论了消相干时间与库仑结合参数，耦合强度，受限长度，色散系数的变化关系. 关键词： 量子点 量子比特 量子信息 消相干

The effect of Coulomb potential to the decoherence of the parabolic quantum dot qubit

On the condition of electric-LO phonon strong coupling in parabolic quantum dot, we obtained the eigenenergy of the ground state and the first excited state, the eigenfuctions of the ground state and the first excited state by using variational method of Pekar type. This system of quantum dot may be employed as a two-level quantum system-qubit. The phonon spontaneous emission causes the decoherence of the qubit. We discussed the relatoion between the decoherence time and the Coulomb binding parameter，the couping strength, the confinement length, and the conefficient dispersion.