Quasi-periodic Wannier-Stark ladders from driven atomic Bloch oscillations

Periodic Wannier\textendashStark ladder structures of the energy resonances associated with Bloch oscillations can be readily modified into quasi-periodic ones that exhibit peculiar self-similar effects. A compact theoretical description of the dynamics of driven Bloch oscillations is developed here within the quasi-momentum representation. We identify a rather viable scheme based on ultracold atomic wavepackets subject to gravity in a driven optical lattice potential where a self-similar scaling could be observed. Its feasibility in terms of realistic experimental parameters is also discussed

A singular light dragging effect

We discuss the phenomenon of upstream bending of a light ray and we anticipate that such an anomalous effect can be observed in a coherently driven sample of cuprous oxide (Cu2O). We here examine the material parameters and the driving configurations that lead to upstream bendings of considerable magnitude

Laser assisted Cherenkov emission in resonant media

We theoretically examine the behaviour of Cherenkov radiation in a lossy, dispersive and resonant medium when emission is assisted by an external electromagnetic field. Under the appropriate coherence conditions for Cherenkov emission, we anticipate a large increase of the emission yield at resonance. Our predictions are implemented by numerical estimates for cuprous oxide (Cu2O)