High-field Zeeman contribution to the trion binding energy

We examine the role of the Zeeman interaction in determining the bound states of the trion at magnetic fields up to 50 T. Polarization-sensitive photoluminescence measurements on the singlet state of the positively charged trion ${(X}^{+})$ in GaAs quantum wells demonstrate a 60% enhancement of the g factor compared to that of the neutral exciton ${(X}_0)$ in the same sample. This leads to a situation in very high fields where the Zeeman splitting of $X^{+}$ is sufficiently large to determine whether a state is bound or not, and so calls for a re-examination of what is meant by the binding energy of few particle systems.