Steady-state Fano coherences in a V-type system driven by polarized incoherent light
Steady-state Fano coherences in a V-type system driven by polarized incoherent light
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DOI：
10.1103/physrevresearch.3.013295
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发表时间：
2020-01
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影响因子：
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通讯作者：
Suyesh Koyu;A. Dodin;P. Brumer;T. Tscherbul
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文献类型：
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作者：
Suyesh Koyu;A. Dodin;P. Brumer;T. Tscherbul
本文研究了在无相干驱动的情况下，偏振非相干光连续泵浦三能级V型系统产生的稳态Fano相干态的性质。当激发态分裂$\Delta$小于自发衰变速率$\gamma$或非相干泵浦速率$r$时，稳态相干态与激发态粒子数之比$\mathcal{C} =（1+\frac{\Delta^2}{\gamma（r+\gamma）}）^{-1}$最大。我们证明了一个有趣的制度存在的$\mathcal{C}$的比率显示最大值作为一个函数的失相率$\gamma_d$。我们归因于令人惊讶的去相诱导增强固定法诺相干性的环境抑制的破坏性干扰的个人在不同的时间产生的非相干激发。我们确定了假想的Fano相干性与耦合到两个独立热浴的一对量子比特之间的非平衡通量，揭示了量子比特网络中的非平衡量子输运与多级量子系统的非相干驱动之间看似无关的现象之间的直接联系。稳态Fano相干性的真实的部分被发现是成比例的偏离的激发态人口从他们的值在热力学平衡，使人们有可能观察到签名的稳态Fano相干性在激发态人口。我们提出了一个通过探测钙原子在偏振和各向同性非相干光激发下发射的总荧光信号来观测稳态Fano相干态的实验方案。我们的分析铺平了道路，进一步的理论和实验研究的非平衡相干稳态热驱动的原子和分子系统，并探索其在生物过程中的潜在作用。
We explore the properties of steady-state Fano coherences generated in a three-level V-system continuously pumped by polarized incoherent light in the absence of coherent driving. The ratio of the stationary coherences to excited-state populations $\mathcal{C} = (1+\frac{\Delta^2}{\gamma(r+\gamma)} )^{-1}$ is maximized when the excited-state splitting $\Delta$ is small compared to either the spontaneous decay rate $\gamma$ or the incoherent pumping rate $r$. We demonstrate that an intriguing regime exists where the $\mathcal{C}$ ratio displays a maximum as a function of the dephasing rate $\gamma_d$. We attribute the surprising dephasing-induced enhancement of stationary Fano coherences to the environmental suppression of destructive interference of individual incoherent excitations generated at different times. We identify the imaginary Fano coherence with the non-equilibrium flux across a pair of qubits coupled to two independent thermal baths, unraveling a direct connection between the seemingly unrelated phenomena of incoherent driving of multilevel quantum systems and non-equilibrium quantum transport in qubit networks. The real part of the steady-state Fano coherence is found to be proportional to the deviation of excited-state populations from their values in thermodynamic equilibrium, making it possible to observe signatures of steady-state Fano coherences in excited-state populations. We put forward an experimental proposal for observing steady-state Fano coherences by detecting the total fluorescence signal emitted by Calcium atoms excited by polarized vs. isotropic incoherent light. Our analysis paves the way toward further theoretical and experimental studies of non-equilibrium coherent steady states in thermally driven atomic and molecular systems, and for the exploration of their potential role in biological processes.