Mojahedi M, Schamiloglu E, Hegeler F, Malloy KJ
Center for High Technology Materials and Department of Electrical and Computer Engineering, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106, USA.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Oct;62(4 Pt B):5758-66. doi: 10.1103/physreve.62.5758.
Single microwave pulses centered at 9.68 GHz with 100-MHz (full width at half maximum) bandwidth are used to evanescently tunnel through a one-dimensional photonic crystal. In a direct time-domain measurement, it is observed that the peak of the tunneling wave packets arrives (440+/-20) ps earlier than the companion free space (air) wave packets. Despite this superluminal behavior, Einstein causality is not violated since the earliest parts of the signal, also known as the Sommerfeld forerunner, remain exactly luminal. The frequency of oscillations and the functional form of the Sommerfeld forerunner for any causal medium are derived.
以9.68吉赫兹为中心、带宽为100兆赫兹（半高全宽）的单个微波脉冲被用于通过一维光子晶体进行倏逝隧穿。在直接时域测量中，观察到隧穿波包的峰值比伴随的自由空间（空气）波包早(440±20)皮秒到达。尽管有这种超光速行为，但爱因斯坦因果律并未被违反，因为信号的最早部分，即所谓的索末菲前驱波，仍然恰好以光速传播。推导了任何因果介质中振荡频率和索末菲前驱波的函数形式。
