Optical readout of charge and spin in a self-assembled quantum dot in a strong magnetic fieldM. Korkusinski1, P. Hawrylak1, A. Babinski2, M. Potemski3, S. Raymond1 and Z. Wasilewski1
1 Institute for Microstructural Sciences, National Research Council - Ottawa, Canada, K1A0R6
2 Institute of Experimental Physics, Warsaw University - Warsaw, Poland
3 Grenoble High Magnetic Field Laboratory, CNRS - Grenoble, France
received 22 May 2007; accepted in final form 28 June 2007; published August 2007
published online 20 July 2007
We present a theory and experiment demonstrating the optical readout of charge and spin in a single InAs/GaAs self-assembled quantum dot. By applying a magnetic field we create the filling-factor-2 quantum Hall singlet phase of the charged exciton. Increasing or decreasing the magnetic field leads to electronic spin-flip transitions and increasing spin polarization. The increasing total spin of electrons appears as a manifold of closely spaced emission lines, while spin flips appear as discontinuities of the emission lines. The number of multiplets and discontinuities measures the number of carriers and their spin. We present a complete analysis of the emission spectrum of a single quantum dot with N = 4 electrons and a single hole, calculated and measured in magnetic fields up to 23 tesla.
78.67.Hc - Quantum dots.
71.70.Gm - Exchange interactions.
71.35.Ji - Excitons in magnetic fields; magnetoexcitons.
© Europhysics Letters Association 2007