自旋-Peierls链中通过非线性声子学实现的异常动态能流
Anomalous dynamical energy flows via nonlinear phononics in spin-Peierls chains
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中文总结 AI 辅助
本研究采用多层非线性声子学架构，通过太赫兹激光驱动红外模式实现自旋-Peierls链的异常动态能流，揭示能量转移受动态阻抗匹配条件调控，明确了连续波与脉冲驱动的不同效应及控制动态磁态的限制。
中文摘要 AI 辅助
我们采用多层非线性声子学架构，研究强二聚化自旋-Peierls链中的非平衡自旋-声子动力学与能量级联。为规避禁止直接激发拉曼活性二聚化模式的线性选择定则，太赫兹激光驱动红外模式，该模式与拉曼晶格位移非线性耦合，进而调制磁交换。借助结合Lindblad主方程二阶累积量展开的键算符形式，我们发现，向磁 sector 的最大能量转移由动态阻抗匹配条件而非未受扰三粒子态密度决定。我们还发现，连续波驱动的持续能量输入会构建高激发密度，对晶格产生严重反作用，使主声子过阻尼，并通过功率展宽模糊磁特征。相反，脉冲的小时间积分能量使响应保持微扰状态，在反作用累积前终止，保留尖锐的类Fano量子干涉。这些见解为控制动态磁态且不淬灭驱动晶格模式建立了限制条件。
英文摘要
We investigate the nonequilibrium spin-phonon dynamics and energy cascades in a strongly dimerized spin-Peierls chain using a multi-tiered nonlinear phononics architecture. To bypass linear selection rules prohibiting the direct excitation of the Raman-active dimerization mode, a terahertz laser drives an infrared mode that nonlinearly couples to the Raman lattice displacement, subsequently modulating the magnetic exchange. Employing a bond-operator formalism with a second-order cumulant expansion of the Lindblad master equation, we show that maximum energy transfer into the magnetic sector is governed by a dynamical impedance-matching condition rather than the unperturbed triplon density of states. We find that the sustained energy input of continuous-wave driving builds high excitation densities that severely back-act on the lattice, overdamping the primary phonon and smearing magnetic features via power broadening. Conversely, the small time-integrated energy of a pulse keeps the response perturbative, terminating before back-action accumulates and preserving sharp Fano-like quantum interferences. These insights establish limits for controlling dynamic magnetic states without quenching the driving lattice modes.
