title: Tuning the nonlocal spin-spin interaction between quantum dots with a magnetic field.
abstract: We describe a device where the nonlocal spin-spin interaction between quantum dots (QDs) can be turned on and off with a small magnetic field. The setup consists of two QDs at the edge of two two-dimensional electron gases (2DEGs). The QDs' spins are coupled through a RKKY-like interaction mediated by the electrons in the 2DEGs. A magnetic field B(z) perpendicular to the plane of the 2DEG is used as a tuning parameter. When the cyclotron radius is commensurate with the interdot distance, the spin-spin interaction is amplified by a few orders of magnitude. The sign of the interaction is controlled by finely tuning B(z). Our setup allows for several dots to be coupled in a linear arrangement and it is not restricted to nearest-neighbor interaction.
authors.affiliation: Instituto Balseiro and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, (8400) San Carlos de Bariloche, Argentina.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Usaj
authors.forename: P
authors.initials: P
authors.lastname: Lustemberg
authors.forename: C A
authors.initials: CA
authors.lastname: Balseiro