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physica status solidi (b)

Controlling spin phases of few electrons in artificial molecules by magnetic fields

Massimo Rontani, Guido Goldoni, Devis Bellucci, Elisa Molinari

Published Oct 23, 2006• 0 citations
Publisher

Abstract

Abstract We investigate the phase diagram of realistic vertically coupled quantum dots under a magnetic field of arbitrary strength and direction. The ground state wave function of four electrons is determined by means of the full configuration interaction method, able to accurately treat electron–electron correlation, which can dominate at experimentally attainable fields. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

DOI
10.1002/pssb.200671511

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Abstract Four‐wave mixing (FWM) optical response from a sample containing a non‐homogeneously broadened ensemble of vertically stacked pairs of quantum dots is studied theoretically. The effects of collective interaction between the dots and their electromagnetic environment are analyzed. It is shown that the shape of the FWM echo is affected by the coupling between the two dots and, to some extent, by the statistics of the ensemble. In the time‐integrated signal, oscillations on picosecond delay time scale appear which lead to a reduction of the coherent response for coupled dots. For longer delays, the evolution is dominated by radiative decay, with the decay rate increasing from Γ to 2Γ(superradiance effect) as the coupling becomes stronger. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)