Inversion of Zeeman splitting of exciton states in InGaAs quantum wells
  Zeeman splitting of quantum-confined states of excitons in InGaAs quantum wells (QWs) is experimentally found to depend strongly on quantization energy. Moreover, it changes sign when the quantization energy increases with a decrease in the QW width. In the 87-nm QW, the sign change is observed for the excited quantum-confined states, which are above the ground state only by a few meV. A two-step approach for the numerical solution of the two-particle Schroedinger equation, taking into account the Coulomb interaction and valence-band coupling, is used for a theoretical justification of the observed phenomenon. The calculated variation of the g-factor convincingly follows the dependencies obtained in the experiments. 
P. S. Grigoryev, O. A. Yugov, S. A. Eliseev, Yu. P. Efimov, V. A.   Lovtcius, V. V. Petrov, V. F. Sapega, and I. V. Ignatiev
cond-mat.mes-hall