摘要
从经典电路理论出发,得到了磁通偏置超导电路的Bloch-Redfield方程,并在二能级近似下,讨论了不同的环境阻抗及耦合效应对磁通量子比特消相干的影响。结果发现:在一定条件下,消相干时间随耦合强度的增加而减小;环境阻抗为纯电阻时,消相干时间随电阻的增加而增加。环境阻抗由RC电路构成时,不同的电路元件对消相干时间的影响不同。
We derive Bloch-Redfield function with flux biased superconducting circuit in the framework classical circuit theory. Under two-level approximation, we discuss the influence of the different environment impedancses and the coupling strength on the decoherence of the magnetic flux qubit. We find that： under certain condition, the decoherence time decreases as the coupling strength increases, and when the environment impedance is pure impedance, the decoherence time increases as the impedance increases while the environment impedance consists of the resistor and capacitor, the influence of the different circuit elements on the decoherence time is different.
出处
《量子光学学报》
CSCD
北大核心
2008年第4期398-406,共9页
Journal of Quantum Optics
基金
江西师范大学青年成长基金(批准号:2006103)
关键词
超导量子电路
磁通量子比特
消相干时间
互感
superconducting quantum circuits
flux qubit
decoherence time
mutual inductance
impedance
