Tunable magnetic property of lateral quantum dot molecules

Abstract

We investigate theoretically magnetic properties of tunable lateral double quantum dots (DQDs) containing few electrons, subjected to spin-orbit interaction (SOI) and vertical magnetic field, using exact diagonalization (ED) method. To circumvent the cumbersome construction of matrix elements of the Hamiltonian, we adopt the modified Gaussian functions to describe atomic-like orbital states of single quantum dots. The numerical artifacts in the single-electron energy spectrum are avoided by separating the full Hilbert space into two sub-spaces. The interplay of SOI and interdot tunnel coupling leads to an oscillatory behaviour in the magnetization at low temperature. Sweeping interdot barrier voltage and adjusting interdot distance produce not only magnetic phase transition but also switches between atomic and molecular orbitals.