Tuning the Nonlocal Spin-Spin Interaction between Quantum Dots with a Magnetic Field

GONZALO USAJ; PABLO LUSTEMBERG,; CARLOS BALSEIRO,

PHYSICAL REVIEW LETTERS

Año: 2005 vol. 94 p. 36803 - 36803

0031-9007

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 twodimensionalelectron gases (2DEGs). The QDs’ spins are coupled through a RKKY-like interaction mediated by the electrons in the 2DEGs. A magnetic field Bz perpendicular to the plane of the 2DEG isused 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 byfinely tuning Bz. Our setup allows for several dots to be coupled in a linear arrangement and it is not restricted to nearest-neighbor interaction.