相关论文: Experimental observation of superluminal group vel…
The refraction of space-time (ST) wave packets offers many fascinating surprises with respect to conventional pulsed beams. In paper (I) of this sequence, we described theoretically the refraction of all families of ST wave packets at…
The propagation of the quantum states of light in dispersive and anisotropic media is a fundamental problem in quantum optics. We present a unified theoretical framework for the propagation of the quantum states of light in…
We experimentally study the group time delay for a light pulse propagating through hot Rb vapor in the presence of a strong coupling field in a $\Lambda$ configuration. We demonstrate that the ultra-slow pulse propagation is transformed…
We show some new properties of the acoustic propagation in two-dimensional sonic crystals, formed by parallel rigid cylinders placed in air. The transmission through slabs of sonic crystals and the associated band structures are considered.…
The electrical properties 2D of packed metallic pentagons have been studied. The characterization of such metallic pentagon heaps (like $i-V$ measurements) has been achieved and has allowed to point out two distinct conduction regimes. They…
Consider a plane monochromatic wave incident on a semi-infinite periodic structure. What happens if the normal component of the transmitted wave group velocity vanishes? At first sight, zero normal component of the transmitted wave group…
Since the forward and backward waves are coupled with each other and a standing wave with no net propagation of energy is formed in the photonic bandgap, it is a commonsense of basic physics that, any kinds of effects associated with wave…
Supersolidity -- a quantum-mechanical phenomenon characterized by the presence of both superfluidity and crystalline order -- was initially envisioned in the context of bulk solid helium, as a possible answer to the question of whether a…
Using a two-photon interference technique, we measure the delay for single-photon wavepackets to be transmitted through a multilayer dielectric mirror, which functions as a ``photonic bandgap'' medium. By varying the angle of incidence, we…
We present the design and fabrication of photonic crystal structures exhibiting electromagnetic bands that are flattened in all crystal directions, i.e., whose frequency variation with wavevector is minimized. Such bands can be used to…
A method is introduced to analyze the degeneracy properties of the band structure of a photonic crystal making use of the super cells. The band structure associated with a super cell of a photonic crystal has degeneracies at the edge of the…
It says in the report$^1$ by Wang et al. that a negative group velocity $u=-c/310$ is obtained and that a pulse advancement shift 62-ns is measured. The authors claim that the negative group velocity is associated with superluminal light…
Light propagation in a photonic crystal infiltrated with polarizable molecules is considered. We demonstrate that the interplay between the spatial dispersion caused by Bragg diffraction and polaritonic frequency dispersion gives rise to…
We report on the observation of broadband (40 THz) bright twin beams through high-gain parametric down-conversion in an aperiodically poled lithium niobate crystal. The output photon number is shown to scale exponentially with the pump…
It is typically assumed that the fluctuations associated with a stationary broadband incoherent field propagate in free space at the speed of light in vacuum c. Here we introduce the concept of 'coherence group velocity', which -- in…
The ability to control wave propagation is of fundamental interest in many areas of physics. Photonic and phononic crystals have proved very useful for this purpose but, because they are based on Bragg interference, these artificial media…
Fluctuations typically destroy long-range order in two-dimensional (2D) systems, posing a fundamental challenge to the existence of exotic states like supersolids, which paradoxically combine solid-like structure with frictionless…
We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded a uniform medium. The frequency band structure is computed using the standard plane-wave expansion method,…
We present the observation of a complete bandgap and collective spin wave excitation in two-dimensional magnonic crystals comprised of arrays of nanoscale antidots and nanodots, respectively. Considering that the frequencies dealt with here…
We report for the first time the bandgap engineering of Tamm plasmon photonic crystals - Tamm plasmon structures of which the metalic layer is periodically patterned into lattice of subwavelength period. By adopting a double period design,…