球壳量子点中电子能态及其量子比特的性质

Electronic States and the Properties of Qubit in Spherical Shell Quantum Dot

通过求解球壳量子点的能量本征方程,得到电子能态,并以两能态叠加构造一个量子比特。对InAs材料的数值计算表明:当电子受限增强时,能量本征值增大。量子比特内电子的概率密度分布与电子的空间坐标和时间有关,在球壳的中心球面上电子出现的概率最大,在球壳边界面出现的概率为零,且各个空间点的概率密度随方位角周期性变化和随时间做周期性振荡,振荡周期随着外径(或内径)的增大而增大。

The electronic states in spherical shell quantum dot are obtained by solving the Schr6dinger equation and a quantum bit is formed by overlying both the ground state ψ000 and excited state ψ020. The numerical results for InAs spherical shell quantum dot indicate that the energy of electron increases when the electron＇ s confinement is strengthened, the probability density distribution of electron in a qubit has something to do with the electron＇ s position in the spherical shell quantum dot and time, there is a maximum in centre spherical surface and zero in boundary surfaces; the probability density of electron in all position makes periodical changing with angle coordinate and periodical oscillating with time, and the oscillating period increases with the outer （or inner） radius increasing.