Strong similarities for relativistic electrons stimulated from electron beams and electron clouds are merging the boundary of wave‐particle duality of electrons, one of which being superposition is Cherenkov radiations. Recent theoretical investigations into quantum Cherenkov effects for cone‐shape particles have hypothesized electron‐spin flip transitions in bound‐ and free‐electron systems like bulk silica and graphene. However, experimental validation of these predictions remains outstanding. Here, analogous phenomena of polariton‐version quantum Cherenkov radiations observed by broadband femtosecond pump‐probe experiments is reported, and demonstrate double‐cone emission processes involving of Cherenkov‐type phonon polaritons (PhPs) and plasmon‐PhPs in ultrashort‐pulse‐stimulated ferroelectric crystals and graphene, respectively. Through component analysis of double‐cone polariton emissions using an empirical quantum dynamics model, the initial polariton dynamics are restored by time translation corrections. The resulting quantum wave packets of PhPs are found to be correlated with femtosecond‐laser‐induced modifications inside ferroelectric lithium niobates, achieving a PhP threshold criterion for ultrasmooth femtosecond laser nanofabrication.

中文翻译：

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将双锥极化激元动力学与超短脉冲受激晶体中的局部飞秒激光修饰相关联


由电子束和电子云激发的相对论电子的强烈相似性正在合并电子的波粒二象性的边界，其中一种叠加是切伦科夫辐射。最近对锥形粒子的量子切伦科夫效应的理论研究假设了本体二氧化硅和石墨烯等束缚和自由电子系统中的电子-自旋翻转跃迁。然而，这些预测的实验验证仍然悬而未决。在这里，报道了通过宽带飞秒泵浦探针实验观察到的极化激元量子切伦科夫辐射的类似现象，并展示了双锥发射过程，分别涉及超短脉冲刺激铁电晶体和石墨烯中切伦科夫型声子极化激元 （PhP） 和等离子体 PhP。通过使用经验量子动力学模型对双锥极化激元发射进行成分分析，通过时间平移校正恢复初始极化激元动力学。发现 PhP 的量子波包与铁电铌酸锂内部的飞秒激光诱导的修饰相关，实现了超光滑飞秒激光纳米制造的 PhP 阈值标准。