Many experimental observations in two dimensional electron gases (2DEG) with a transverse magnetic field, including quantum hall effect and transverse magnetic focusing, rely on the existence of edge states. The possibility of building quantum point contacts and quantum dots (QD) at the edge of 2DEG, that couple with edge states, opens new opportunities for the fast developing fields of spintronics. We first analyze focusing experiments including the effect of spin orbit interaction and show how polarized currents are generated. Then we show how the effective non-local exchange interaction between QD’s mediated by edge states can be tuned with a small magnetic field. The proposal is based precisely on the possibility of focusing the electrons that interact with one quantum dot onto the other by the action of the external field.

Centro Atómico Bariloche, Bariloche, Argentine