Theory of electron-hole exchange interaction in double quantum dots

Abstract

A theory of electron-hole exchange interaction in vertically stacked double quantum dots is developed. This theory was built up from the full interaction Hamiltonian of two coupled dots, taking into account both of the macroscopic and microscopic natures of particle wave functions. In the basis of S-type Fock-Darwin orbitals, compact formulations for electro-hole exchange terms responsible for the fine structure splitting of spin exciton states as functions of material parameters, geometric structure of dots, and the strength of external field are explicitly derived. Significant reduction of the splitting, down to 50% of the magnitude of such energy in single dot case, is observed as the system is switched into the near-resonance regime. (C) WILEY-VCH Verlage GmbH & Co. KGaA, Weinheim