Figure 1: Dynamic nuclear polarization at zero applied field.
From: Nuclear magnetization in gallium arsenide quantum dots at zero magnetic field
(a) Hyperfine interaction between a single electron and the nuclear spins of the quantum dot lattice. (b) Circular polarization degree of emission (error ±1% included in symbol height) of neutral exciton X0 (squares) and charged excitons X+ (triangles) and X− (circles) as a function of excitation laser power using σ+ polarization. (c) Energy difference between σ+ and σ− polarized emission for X+ (triangles) and X− (circles): Overhauser shift ∝ average nuclear spin ‹Iz›. Error bars correspond to spectral precision (d) X+PL spectra σ+ (triangles) and σ−(circles) polarized at max. laser power. (e) Overhauser shift as a function of the measured X+ PL polarization with varying laser excitation polarization at constant power of 2 μW. Error bars correspond to spectral precision.
