Exchange energy enhancedg-factors obtained from Landau fan diagrams at low magnetic fields

Abstract

We report on measurement of the electron-hole effective $g$-factors (${g}_{\mathrm{eff}}^{*}$) depending on electron filling factors $\ensuremath{\nu}$ from magnetophotoluminescence spectroscopy at low magnetic fields $B<1$ T in low electron density regime in a GaAs/Al${}_{0.33}$Ga${}_{0.67}$As-gated quantum well. Enhancement of ${g}_{\mathrm{eff}}^{*}$ at odd $\ensuremath{\nu}$ is observed. The oscillatory behavior of ${g}_{\mathrm{eff}}^{*}$ is compared with results of a theory that takes into account the lowest-order exchange interaction of the screened Coulomb interaction. Good agreement of the observed ${g}_{\mathrm{eff}}^{*}$ with theoretical results is obtained except $\ensuremath{\nu}$ at around 3. The enhancement of ${g}_{\mathrm{eff}}^{*}$ at even $\ensuremath{\nu}$ with decrease in electron density has not been observed.