A quantum memory component including a quantum dot molecule having first and second quantum dots provided in respective first and second layers separated by a barrier layer; an exciton comprising an electron and hole bound state in said quantum dot molecule, the spin state of said exciton forming a qubit; first and second electrical contacts respectively provided below the first quantum dot and above the second quantum dot; a voltage source to apply an electric field across said quantum dot molecule; a controller to modulate the electric field across the quantum dot molecule, including an information acquiring circuit to acquire information concerning the relationship between fine structure splitting of the exciton and the applied electric field and a timing circuit to allow switching of the exciton from an indirect configuration to a direct configuration at predetermined times derived from the fine structure splitting.