Spin-orbit qubit using quantum dots

Methods and apparatus of quantum information processing using quantum dots are provided.  Electrons from a 2DEG are confined to the quantum dots and subjected to a magnetic field having a component directed parallel to the interface.  Due to interfacial asymmetries, there is created an effective magnetic field that perturbs the energies of the spin states via an interfacial spin-orbit (SO) interaction.  This SO interaction is utilized to controllably produce rotations of the electronic spin state, such as X-rotations of the electronic spin state in a double quantum dot (DQD) singlet-triplet (ST) qubit.  The desired state rotations are controlled solely by the use of electrical pulses.