Calculation of Exchange Energy in Double Quantum Dots Using COMSOL Wave Functions

Heitler-London(HL) and Hund-Mulliken(HM) approximations were applied in microscopic computations for double quantum dot (DQDs) spin qubits. The J- interaction between triplet and singlet states in a linked double quantum dot (DQD) at (Si/SiO2) interface using COMSOL Multiphysics wave functions was estimated. By evaluating different potential, this calculation is performed within a specified region of interest. We evaluated these findings in relation to a situation in which Fock-Darwin (FD) states are used and a precisely known solution of a one-dimensional Schrödinger equation exists. Our study reveals the effectiveness of the applied method and provides interesting investigation of the reliability and accuracy of the computational method used.