Non-Markovian master equation for a damped oscillator with time-varying parameters
Non-Markovian master equation for a damped oscillator with time-varying parameters
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DOI：
10.1103/physreva.81.052105
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发表时间：
2010-03
影响因子：
2.9
通讯作者：
K. Chang;C. K. Law
中科院分区：
文献类型：
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作者：
K. Chang;C. K. Law
我们导出了一个精确的非马尔可夫主方程，它将以前的工作[Hu，Paz和Zhang，Phys.Rev.D45，2843（1992）]推广到具有时变参数的阻尼谐振子。这是通过利用系统的线性和海森堡图像中的算子解来实现的。我们的方程支配的非马尔可夫量子动力学时，系统是由外部设备调制。作为应用，我们将我们的方程的奇偶踢解耦问题。当系统由{pi}脉冲驱动时，主方程中的时间依赖性耗散系数被大幅修改。为了使相干保护有效，我们的数值结果表明，踢周期应该短于记忆时间的浴。还讨论了在欧姆浴中使用软脉冲的效果。
We derive an exact non-Markovian master equation that generalizes the previous work [Hu, Paz and Zhang, Phys. Rev. D 45, 2843 (1992)] to damped harmonic oscillators with time-varying parameters. This is achieved by exploiting the linearity of the system and operator solution in Heisenberg picture. Our equation governs the non-Markovian quantum dynamics when the system is modulated by external devices. As an application, we apply our equation to parity kick decoupling problems. The time-dependent dissipative coefficients in the master equation are shown to be modified drastically when the system is driven by {pi} pulses. For coherence protection to be effective, our numerical results indicate that kicking period should be shorter than memory time of the bath. The effects of using soft pulses in an ohmic bath are also discussed.