涨落对几何量子门的影响

Influence of the noise on geometric quantum gates

研究了几何量子门抵抗控制外场随机涨落的能力。在用周期微扰近似代替随机涨落下的研究表明:无论是绝热的Berry几何相还是非绝热的Aharonov-Anandan(A-A)几何相,其抗涨落的能力都和其对应的动力学相位的抗涨落能力相当。而Berry相位(几何相位,动力学相位)的抗涨落能力要远强于A-A位相,可视为由绝热近似导致这种差别。此外验证了利用正交态方案构造的量子门具有很强的抗涨落能力。

The ability of geometric quantum gate against the fluctuations of control external field was researched. We replace the random fluctuations by the periodic perturbation. In this approximation, the result shows that no matter the Berry geometry phase or the Aharonov- Anandan （A-A）＂geometry phase has the same ability against the stochastic fluctuations as their corresponding dynamics phases. And numerical results also justify that the Berry phase is more powerful to resist the external field fluctuation than that of the A-A phase. We believe that this distinction is caused by adiabatic approximation purely. Lastly, it is validated that the geometry quantum gates constructed by an orthogonal state scheme are more powerful. against the fluctuations.