AI 中文总结
该研究揭示双曲介质中存在互补时域效应，利用双曲时间界面可实现p偏振波的方向选择性冻结、放大等虚频动力学，无需Floquet周期性，为波调控提供新途径。
AI 中文摘要
双曲介质以其能将常规介质中倏逝的高k分量通过开放等频轮廓转化为传播的体波而闻名。本文揭示了一种互补的时域效应：在突然转变为等效非色散双曲态后，全波矢守恒会使不定色散将动量空间划分为实频、零频和纯虚频区域。因此，p偏振波会根据其守恒的波矢方向，发生常规时域散射、临界磁场冻结或指数增长与衰减，而s偏振波则保持在实频区域。第二个时域边界会将冻结或放大的场以原始频率释放为传播波。分析时域边界理论、k空间脉冲重构及时域有限差分模拟均证实了这些动力学过程。这些结果确立了双曲时域边界是一种紧凑的途径，可实现无Floquet周期性的方向选择性虚频动力学与波放大。
英文摘要
Hyperbolic media are well known for converting high k-components that are evanescent in conventional dielectrics into propagating bulk waves through their open equifrequency contours. Here, we reveal a complementary temporal effect: after a sudden transition into an effectively nondispersive hyperbolic state, conservation of the full wavevector causes the indefinite dispersion to partition momentum space into real-, zero-, and purely imaginary-frequency regimes. Consequently, p-polarized waves undergo conventional temporal scattering, critical magnetic-field freezing, or exponential growth and decay, depending solely on their conserved wavevector direction, whereas s-polarized waves remain in the real-frequency regime. A second temporal boundary releases the frozen or amplified fields into propagating waves at original frequency. Analytical temporal boundary theory, k-space pulse reconstruction, and finite-difference time-domain simulations corroborate these dynamics. These results establish hyperbolic temporal boundaries as a compact route to direction-selective imaginary frequency dynamics and wave amplification without Floquet periodicity.
Comments18 pages, 4 figures
