纳米管中极化子量子比特的温度特性

Temperature Property of the Polaron Qubit in Nanotubes

利用求解能量本征方程、幺正变换和变分相结合的方法,研究纳米管中极化子量子比特的温度性质。数值计算结果表明:量子比特内的电子在各个空间点的概率密度均随时间做周期性振荡,不同空间点的概率密度幅值不同,纳米管中心层概率密度幅值最大,管界面处概率密度幅值为零。数值计算结果还表明:温度不改变量子比特的振荡周期随纳米管内径的增大(或外径的减小)而减小的趋势;振荡周期随温度的降低而减小,但是当温度低至晶格振动能量不足以激发实声子时,振荡周期与温度无关;振荡周期随耦合强度的增大而增大。

The temperature property of the polaron qubit in nanotubes was studied by solving precisely the time-independent Schrdinger equation,the LLP unitary transformations and the variation method.The numerical results indicate that probability density of electron at each space point in qubit does periodicity oscillating with time,but their probability density amplitude is different.The probability density amplitude is maximum at the center layer and is zero at the nanotube interface.Numerical results also show that the temperature doesn′t change the trend of oscillating period of qubit which decreases with increasing nanotube inside radius(or decreasing nanotube outside radius).The oscillating period of qubit decreases with weakening electron-LO phonon coupling strength or falling temperature,but it has nothing to do with the temperature if the temperature is low and the lattice vibration energy is not high enough to stimulate the real phonons.