Charge localization and dynamical spin locking in double quantum dots driven by ac magnetic fields

We investigate electron localization and dynamical spin locking induced by ac magnetic fields in double quantum dots. We demonstrate that by tuning the ac magnetic fields parameters, i.e., the field intensity, frequency, and the phase difference between the fields within each dot, coherent destruction of tunneling (and thus charge localization) can be achieved. We show that in contrast with ac electric fields, ac magnetic fields are able to induce spin locking, i.e., to freeze the electronic spin, at certain field parameters. We show how the symmetry of the Hamiltonian determines the quasienergy spectrum which presents degeneracies at certain field parameters, and how it is reflected in the charge and spin dynamics.