hide
Free keywords:
quantum dot; magneto-luminescence; interdiffusion; InAs/GaAs; self-assembled; in-plane effective mass and Ga content
Abstract:
A set of self-assembled InAs/GaAs quantum dot (QD) samples annealed at
various temperatures for 30 s was studied using
magneto-photoluminescence up to 28T. Blueshifis increasing with
annealing temperature, due to Ga-As interchange at the QD-barrier
interface, are correlated with a reduction in inhomogeneous broadening
and a reduction in inter-sublevel spacing. These new sample properties
allow us to obtain clear crossing patterns closely matched with
Fock-Darwin diagrams where the field applied perpendicular to the QD
plane lifts the state degeneracies. In the limit that in-plane electron
and hole wavefunction extension is the same, the splitting of the
p-shell with magnetic field is inversely proportional to the in-plane
exciton reduced mass. We use this to obtain the evolution of the latter
with intermixing, and compare with predictions of single-particle k * p
calculations.
