论文标题

短脉冲的超材料

Short-Pulsed Metamaterials

论文作者

Rizza, Carlo, Castaldi, Giuseppe, Galdi, Vincenzo

论文摘要

我们研究了一类暂时的超材料,其特征是持续时间的时变介电介电常数波形比特征波动力学时间尺度小得多。在空间和时间超材料之间的类比中,这种短脉冲状态可以看作是元时间的时间对应物。我们引入了一种一般而紧凑的分析形式主义,用于建模短脉冲的超材料与电磁波包的相互作用。具体而言,我们阐明了局部和非局部效应的作用,以及时间反转对称性的破坏,并显示如何利用它们执行基本模拟计算,例如第一和第二个衍生物。我们的理论对全波数值模拟进行了验证,提出了一种在不依赖于长时间周期性的时间调制的情况下操纵电磁波的新途径。正如传统(空间)超材料的技术生存能力和实际适用性中发挥了关键作用一样,短脉冲的超材料可能会催化时间和时空超材料的发展。

We study a class of temporal metamaterials characterized by time-varying dielectric permittivity waveforms of duration much smaller than the characteristic wave-dynamical timescale. In the analogy between spatial and temporal metamaterials, such a short-pulsed regime can be viewed as the temporal counterpart of metasurfaces. We introduce a general and compact analytical formalism for modeling the interaction of a short-pulsed metamaterial with an electromagnetic wavepacket. Specifically, we elucidate the role of local and nonlocal effects, as well as of the time-reversal symmetry breaking, and we show how they can be harnessed to perform elementary analog computing, such as first and second derivatives. Our theory, validated against full-wave numerical simulations, suggests a novel route for manipulating electromagnetic waves without relying on long, periodic temporal modulations. Just as metasurfaces have played a pivotal role in the technological viability and practical applicability of conventional (spatial) metamaterials, short-pulsed metamaterials may catalyze the development of temporal and space-time metamaterials.

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