We calculate the transverse effective charges of zinc-blende compound semiconductors using Harrison’s tight-binding model to describe the electronic structure. Our results, which are essentially exact within the model, are found to be in much better agreement with experiment than previous perturbation-theory estimates. Efforts to improve the results by using more sophisticated variants of the t...

Cold atomic gases placed in optical lattice potentials offer a unique tool to study simple tight binding models. Both the standard cases known from the condensed matter theory as well as novel situations may be addressed. Cold atoms setting allows for a precise control of parameters of the systems discussed, stimulating new questions and problems. The attempts to treat disorder in a controlled ...

Condensed matter physics at room temperature usually assumes that electrons in conductors can be described as spatially narrow wave packets - contrast to what the Schr\"odinger equation would predict. How a finite-temperature environment localize functions is still being debated. Here, we represent by fluctuating potential and investigate different unravellings of Lindblad describes one-dimensi...