Magneto-optical properties of strain-inducedInxGa1−xAsparabolic quantum dots

Abstract

We have investigated the Zeeman splitting in strained In x Ga 1Ϫx As quantum dots with different quantization energies by means of magnetoluminescence. A multifold splitting of ⌸ and ⌬ states is observed due to lifted degeneracy of mϾ0 states. The experimental data were systematically compared to the diamagnetic and Zeeman shift of the single-particle states, taking into account the details of the valence-band structure and the spin splitting. Our data indicate that excitonic effects are negligible and that the magneto-optical properties of these strongly confined dots can be described rather accurately within the single-particle model. ͓S0163-1829͑98͒02116-X͔

Electron-Hole Correlation in Quantum Dots under a High Magnetic Field (up to 45 T)

“…The QD consist of a 8 nm thick In 0.2 Ga 0. 8 As quantum well (QW) 4832 0031-9007͞99͞83(23)͞4832(4)$15.00 © 1999 The American Physical Society buried by a GaAs barrier of thickness 5 nm. Selforganized InP islands (stressors) are grown on the GaAs surface in order to induce a paraboliclike strain potential which laterally confines the carriers in the InGaAs QW underneath the stressor.…”

“…The Darwin-Fock states in the dots were analyzed by the single particle Luttinger-Kohn method [7][8][9] as well as by the effective mass many-electron many-hole Hartree-Fock method, whereas the influence of the direct and exchange Coulomb interaction on the magnetic dispersion of luminescence as a function of the number of confined carriers was studied by the Hartree-Fock method. The total many particle wave function is a direct product of the electron and the hole Slater determinants with single electron and single hole orbitals c …”

“…3, we have processed each QD and QW magnetoluminescence spectrum by a Gaussian deconvolution, following the procedure explained in our previous paper [8]. The lifting of degeneracy of the excited states (Zeeman effect) is clearly observable at low fields.…”

Effects of few-particle interaction on the atomiclike levels of a single strain-induced quantum dot

“…This system has never been investigated by local spectroscopy so far, but for an intriguing nearfield luminescence experiment in which no atomiclike features were observed, 11 despite the excellent zerodimensional characteristics shown recently by the same samples. 2,[12][13][14] The photoluminescence ͑PL͒ of the single dot is measured with increasing the number of e-h pairs, ranging from 1 to approximately 20. At low injection powers, corresponding to an average number of only a few e-h pairs, we do observe the appearance of correlated exciton lines, associated with the formation of biexcitons, on the low-energy side of the ground level transition.…”

Mechanical nanomanipulation of single strain-induced semiconductor quantum dots

“…4 Despite the enormous progress achieved in sample quality, the PL spectra dots are broadened by inhomogeneities in the size distribution of the confining potential. 5 In the present work we show that the dot potential can be, to some extent, tailored by mechanically removing some of the stressor material using a tuning fork shear force microscope. Figure 1 shows the structure of the sample under investigation.…”