Integer filling factor phases in vertical diatomic artificial molecules

We investigate integer filling factor phases of many-N-electron vertically coupled semiconductor quantum dot artificial molecules when the inter-dot coupling is strong and weak. The experimental results are analyzed within local-spin density- functional theory. Maximum density droplets composed of electrons in both bonding and anti-bonding, or just bonding states are revealed. Interesting isospin physics (i.e., isospin transitions) can occur particularly when the inter-dot coupling is reduced.