Open quantum systems in thermal nonergodic environments
Open quantum systems in thermal nonergodic environments
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DOI：
10.1103/physreva.103.032204
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发表时间：
2019-10
影响因子：
2.9
通讯作者：
C. A. Parra-Murillo;Max Bramberger;C. Hubig;I. de Vega
中科院分区：
文献类型：
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作者：
C. A. Parra-Murillo;Max Bramberger;C. Hubig;I. de Vega
一个开放系统的动力学特性决定于它所处环境的关联函数C_B（t）。我们证明了对于热非谐波环境$C_B（t）$可能不衰减到零，而是衰减到一个偏移量，$C_0>0$。这种偏移的存在取决于环境本征态结构，以及它是否满足本征态热化假设。此外，我们还指出，当C_0>0时，弱耦合近似将变得不准确，从而阻止了开放系统的热化。最后，对于一个现实的环境中的染料分子，我们使用矩阵产品状态（MPS）的偏移的出现，并讨论其链接到1/f噪声频谱，与以前的模型相比，扩展到零频率。因此，我们的结果可能与描述量子技术设备（如超导量子比特）中的耗散有关，已知这些设备会受到这种噪声的影响。
The dynamics of an open system crucially depends on the correlation function of its environment, $C_B(t)$. We show that for thermal non-Harmonic environments $C_B(t)$ may not decay to zero but to an offset, $C_0>0$. The presence of such offset is determined by the environment eigenstate structure, and whether it fulfills or not the eigenstate thermalization hypothesis. Moreover, we show that a $C_0>0$ could render the weak coupling approximation inaccurate and prevent the open system to thermalize. Finally, for a realistic environment of dye molecules, we show the emergence of the offset by using matrix product states (MPS), and discuss its link to a 1/f noise spectrum that, in contrast to previous models, extends to zero frequencies. Thus, our results may be relevant in describing dissipation in quantum technological devices like superconducting qubits, which are known to be affected by such noise.