Far-infrared response of quantum dots: filling factor dependence at high magnetic fields
Institut für Theoretische Physik, Universität
Regensburg, 93040 Regensburg, Germany
Accepted: 15 July 1996
In recent experiments by Bollweg et al. (Phys. Rev. Lett., 76 (1996) 2774) a novel feature was observed in the far-infrared absorption spectra of quantum dots: the resonance frequency of the low-lying mode exhibits small oscillations in dependence on the magnetic field. By calculating the self-consistent far-infrared response of electrons in quantum dots, we can give an explanation for this behavior. For high magnetic fields, the occupation of electron states in the quantum dot can be related to a filling factor defined for the density in the center of the dot. We trace back the oscillations in the mode to an oscillatory filling factor dependence of the radial extension of the electron density.
PACS: 73.20.Dx – Electron states in low-dimensional structures (including quantum wells, super lattices, layer structures, and intercalation compounds) / 73.20.Mf – Collective excitations (including plasmons and other charge-density excitations) / 71.45.Gm – Exchange, correlation, dielectric and magnetic functions, plasmons
© EDP Sciences, 1996