摘要
运用量子轨迹和量子Monte Carlo仿真的方法,研究耗散退相干对周期驱动的量子Harper(quantum kicked Harper,QKH)模型量子计算的影响.数值仿真结果表明,一定强度的耗散干扰将破坏QKH特征状态的动态局域化以及相空间的随机网结构.以相位阻尼信道噪声模型为例分析了保真度的衰减规律以及可信计算时间尺度.与静态干扰相比,在干扰强度小于某一阈值时,耗散干扰下的可信计算时间尺度随量子比特的增加而快速下降;而在干扰强度大于该阈值时,静态干扰下的可信计算时间尺度下降更快.
The effects of the dissipative decoherence on the quantum computation of the quantum kicked Harper （QKH） model are investigated using the quantum trajectory approach and the quantum Monte Carlo method. The simulation shows that the dynamical localization for the QKH model and the stochastic web in phase space are destroyed by moderate levels of dissipation. Taking the phase damping channel as the noise model, the universal law for fidelity decay and the timescales of reliable computation are analyzed. Compared with the static imperfections, the timescales for reliable computation of the dissipative system drop more quickly with the increase of the number of qubits when the decay rate is under a certain threshold. While above the threshold, the timescales drop more quickly in the presence of static imperfections.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第2期689-695,共7页
Acta Physica Sinica
