量子耗散与兰姆位移对高次谐波产生的阶次依赖调制

中文摘要 AI 辅助

多体环境通常作为热浴被纳入量子动力学中，热浴会引发兰姆位移和量子耗散。在传统图景中，这种环境耦合预期会导致光谱信号的抑制和展宽。在本信中，我们利用林德blad主方程，研究了通过偶极-偶极相互作用与热浴耦合的二能级系统中的高次谐波产生（HHG）。研究发现，环境效应并非简单地抑制谐波效率。相反，当耦合谱密度的截止频率超过能级间距时，环境实际上可以增强谐波产率。进一步分析揭示，这种增强源于兰姆位移引起的强烈能级涨落。同时，环境的影响表现出对谐波阶次的明显依赖性，对低阶和高阶谐波展现出截然不同的行为。我们的结果挑战了均匀阻尼的常见弛豫时间图景，并为环境调控HHG建立了一个微观的、阶次依赖的机制，对固态阿秒光谱学和量子材料工程具有直接意义。

英文摘要

Many-body environments are conventionally incorporated into quantum dynamics as heat baths, which induce a Lamb shift and quantum dissipation. In the traditional picture, such environmental coupling is expected to induce suppression and broadening of spectral signals. In this letter, we investigate high-order harmonic generation (HHG) in a two-level system coupled to a heat bath via dipole-dipole interactions using the Lindblad master equation. It is found that the environmental effect does not simply suppress the harmonic efficiency. Instead, when the cutoff frequency of the coupling spectral density exceeds the energy-level spacing, the environment can actually enhance the harmonic yield. Further analysis reveals that this enhancement originates from intense level fluctuations induced by the Lamb shift. Meanwhile, the environmental influence exhibits a distinct dependence on harmonic order, manifesting clearly different behaviors for lower and higher harmonics. Our results challenge the common relaxation-time picture of uniform damping and establish a microscopic, order-dependent mechanism for environmental control of HHG, with direct implications for solid-state attosecond spectroscopy and quantum material engineering.

发表机构

• Nanjing University of Science and Technology（南京理工大学）
• East China Normal University（华东师范大学）

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