Abstract
Nonlinear Zeeman splitting of neutral excitons is observed in composition-engineered InGaAs self-assembled quantum dots, and its microscopic origin is explained. Eight-band simulations, performed using realistic dot parameters extracted from cross-sectional scanning tunneling microscopy measurements, reveal that a quadratic contribution to the Zeeman energy originates from a spin-dependent mixing of heavy- and light-hole orbital states in the dot. The dilute In composition () and large lateral size (40–50 nm) of the quantum dots investigated are shown to strongly enhance the nonlinear contribution to the excitonic Zeeman gap, providing a blueprint to enhance such magnetic nonlinearities via growth engineering of the quantum dots.
- Received 12 December 2011
DOI:https://doi.org/10.1103/PhysRevB.85.165433
©2012 American Physical Society