Optical Spectroscopy of Spins in Coupled Quantum Dots

Abstract

Vertically stacked pairs of quantum dots can be coupled together by the tun-neling of either electrons or holes. Such pairs of coupled dots provide a unique opportunity to study the interactions between spins. We review experimentally measured spectra of coupled quantum dots and explain the interactions that give rise to the spin fine structure. The formation of molecular states through tunnel coupling also leads to unique properties for spins confined in these molecular states. We review and explain resonant changes in the single-spin g factor for holes in the molecular states of coupled quantum dots. The orbital character of molecular states is determined by spin-orbit interactions.