Optically detected magnetic resonance at the quadrupole-split nuclear states in (In,Ga)As/GaAs quantum dots

Abstract

Nuclear-magnetic resonances were detected optically in an ensemble of singly charged (In,Ga)As/GaAs quantum dots. The resonances were found in the magnetic field dependence of photoluminescence polarization (Hanle curve) when applying a radio frequency (RF) field. The frequency dependences of the resonances allow us to ascribe them to transitions between Zeeman states of the $^{71}\text{G}\text{a}$ and $^{75}\text{A}\text{s}$ nuclei perturbed by quadrupole interaction. Applying an RF-field sweep over a wide frequency range results in a notable narrowing of the Hanle curve, which can be explained by suppression of dynamic nuclear polarization that otherwise is stabilized by the quadrupole splitting.