Linear combination of harmonic orbitals and configuration interaction method for the voltage control of exchange interaction in gated lateral quantum dot networks

We present a computational LCHO-CI approach allowing for the simulation of exchange interactions in gated lateral quantum dot networks. The approach is based on single-particle states calculated using a linear combination of harmonic orbitals (LCHOs) of each of the dots and a configuration interaction (CI) approach to the interacting electron problem. The LCHO-CI method is applied to a network of three quantum dots with one-electron spin per dot, and a Heisenberg spin Hamiltonian is derived. The manipulation of spin states of a three-spin molecule by applying bias to one of the dots is demonstrated and related to the bias dependence of effective exchange interaction parameters.