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arXiv 1402.6547quant-phmath-phmath.MP
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周期强迫对退相干的抑制

Suppression of Decoherence by Periodic Forcing

Volker Bach, Walter de Siqueira Pedra, Marco Merkli, Israel Michael Sigal

摘要:

我们考虑一个耦合到热库的有限维量子系统,该系统受到时间周期的能量守恒强迫。我们发现,如果满足一定的动力学解耦条件,那么周期性强迫抵消水库引起的退相干:对于小系统水库耦合$λ$和小强迫周期$T$,系统动力学近似的能量守恒和非耗散动力学,它保持凝聚力。对于达到$(λT)^{-1}$阶的时间,真实动态与近似动态之间的差异大小为$λ+T$。我们的方法是严格的,结合Floquet和频谱变形理论。我们说明了我们的自旋费米子模型的结果,并恢复以前已知的,pathologistically获得的结果。

英文摘要:

We consider a finite-dimensional quantum system coupled to a thermal reservoir and subject to a time-periodic, energy conserving forcing. We show that, if a certain dynamical decoupling condition is fulfilled, then the periodic forcing counteracts the decoherence induced by the reservoir: for small system-reservoir coupling $λ$ and small forcing period $T$, the system dynamics is approximated by an energy conserving and non-dissipative dynamics, which preserves coherences. For times up to order $(λT)^{-1}$, the difference between the true and approximated dynamics is of size $λ+T$. Our approach is rigorous and combines Floquet and spectral deformation theory. We illustrate our results on the spin-fermion model and recover previously known, heuristically obtained results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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