Measurement of Superluminal optical tunneling times in double-barrier photonic bandgaps

The meaning of group delay in barrier tunneling: A re-examination of superluminal group velocities

We show that the group delay in tunneling is not a traversal time but a lifetime of stored energy or stored probability escaping through both ends of the barrier. Because it is a lifetime associated with both forward (transmitted) and backward (reflected) fluxes, it cannot be used to define a group velocity for forward transit in cases where a wavepacket is mostly reflected. For photonic tunneling barriers the group delay is identical to the dwell time which is also a property of an entire wave function with reflected and transmitted components. Theoretical predictions and experimental reports…

Superluminal tunneling of microwaves in smoothly varying transmission lines

Tunneling of microwaves through a smooth barrier in a transmission line is considered. In contrast to standard wave barriers, we study the case where the dielectric permittivity is positive, and the barrier is caused by the inhomogeneous dielectric profile. It is found that reflectionless, superluminal tunneling can take place for waves with a finite spectral width. The consequences of these findings are discussed, and an experimental setup testing our predictions is proposed.

非厄米模型能带结构上的不动点：带隙中的扩展态与理想超光速隧穿

Fixed points on band structures of non-Hermitian models: Extended states in the bandgap and ideal superluminal tunneling

本文在一维PT对称非厄米电磁模型中提出能带结构“不动点”概念，揭示其可导致带隙扩展态和理想超光速隧穿现象。

Virtual photons in macroscopic tunneling

Tunnelling processes are thought to proceed via virtual waves due to observed superluminal (faster than light) signal speeds. Some assume such speeds must violate causality. These assumptions contradict, for instance, superluminally tunnelled music and optical tunnelling couplers applied in fiber communication. Recently tunnelling barriers were conjectured to be cavities, wherein the tunnelled output signal is not causally related with the input. The tests described here resolve that tunnelling waves are virtual, propagations are superluminal, and causality is preserved.

光子时间莫尔超晶格中的动量平带与超光速传播

Momentum flatband and superluminal propagation in a photonic time Moiré superlattice

本文提出光子时间莫尔超晶格，通过叠加两个不同周期光子时间晶体实现动量平带，该平带具有无限大群速度，支持更稳定的超光速脉冲传播。

基于波粒二象性的超光速现象解释及拟议光学实验

Explanation of Superluminal Phenomena Based on Wave-Particle Duality and Proposed Optical Experiments

基于光子波粒二象性解释超光速现象，指出超光速仅发生在相干长度内且不违反因果律，并提议光学实验验证。