Interplay between Zeeman coupling and swap action in spin-based quantum computer models: Error correction in inhomogeneous magnetic fields

Inhomogeneous magnetic fields were applied to study the interplay between Zeeman coupling and exchange-induced swap action in a spin-based quantum dot quantum computer model. Decoherence induced by a fluctuating inhomogeneous transverse field may turn out to be an important extrinsic decoherence channel for the quantum dot quantum computer (QDQC) operations. Swap errors caused by the inhomogeneous field are estimated quantitatively. Error correction is possible in the presence of nonuniform magnetic fields in realistic structures.