Fermi-edge singularities in the mesoscopic x-ray edge problem.
We study the x-ray edge problem for a chaotic quantum dot or nanoparticle displaying mesoscopic fluctuations. In the bulk, x-ray physics is known to produce Fermi-edge singularities-deviations from the naively expected photoabsorption cross section in the form of a peaked or rounded edge. For a coherent system with chaotic dynamics, we find substantial changes; in particular, a photoabsorption cross section showing a rounded edge in the bulk will change to a slightly peaked edge on average as the system size is reduced to a mesoscopic (coherent) scale.
Hentschel
Martina
M
Department of Physics, Duke University, Box 90305, Durham, North Carolina 27708-0305, USA.
Ullmo
Denis
D
Baranger
Harold U
HU