Effect of an inhomogeneous external magnetic field on the electronic coupling of quantum dot molecule

The electron spins are a candidate for one or two qubits, which, when located in semiconductor double quantum dots. The desired two-qubit coupling is provided by a combination of the Coulomb interaction and the Pauli exclusion principle. The, coupling between the spin can be switched on and off via externally controlled a uniform magnetic field. In the experimental environment of the system an inhomogeneous magnetic field inevitably appears and added to the homogenous applied magnetic field. In this work, we study a two-electron quantum dot molecule in an inhomogeneous magnetic field. We consider theoretically the interplay between Zeeman coupling and exchange induced swap action in spin-based double quantum dot quantum computer. (C) 2003 Elsevier Science B.V. All rights reserved.