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It is well known that photons carrying momentum ħk exert a positive pressure on an object in vacuum. However, whether photons push or pull an object immersed inside a dielectric medium is not so straightforward due to the century-old debate associated with the definition of photon momentum inside dielectrics [1-2]. This question becomes even more puzzling with the advent of metamaterials, which can...
It is know that photonic crystals with Dirac-like conical dispersions at k = 0 derived from monopole and dipole excitations can serve as a “classical system” with zero-refractiveindex [1]. We will show that such a system also behaves as if it is a “quantum-like system” with pseudo-spin 1 [2]. In some dielectric photonic crystals exhibiting conical dispersions at k = 0, the eigenmodes can be described...
Electromagnetic wave induced forces have been extensively studied for decades. It has been well known that for an electromagnetic wave propagating in vacuum the photons carrying momentum exert a positive photon pressure on an object. However, a metamaterial can have a negative effective refractive index, in which case the wave vector is directed towards the source of radiation. In such a medium, should...
Electromagnetic wave or light-induced forces have been extensively studied for decades. It has been well known that for an electromagnetic wave propagating in vacuum the photons carrying momentum ħk exert a positive photon pressure on an object. However, in a metamaterial with a negative refractive index, the wave vector k is directed towards the source of radiation. In this case, should electromagnetic...
It is always a challenge to realize extreme and unusual values of refractive index for a broad range of frequencies. We show that when water is covered by a thick, rigid and unmovable plate, it behaves like a medium with zero refractive index for water waves at any frequency. Hence, by covering water with a plate of a concave or rectangular shape, water waves can be focused or collimated in a broad...
In this talk, we will discuss some special wave manipulation effects that can be achieved using “graded” metamaterials, i.e. the effective permittivity and permeability have spatial variation. We will also discuss some interesting effects when light interact with metamaterials. In particular, we will show that under some special circumstances, light can attract metamaterials, although we might expect...
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