Substitutional nickel impurities in diamond: Decoherence-free subspaces for quantum information processing
Optical Science and Technology Center and Department of Physics and Astronomy, University of Iowa Iowa City, IA 52242, USA
Received: 8 July 2012
Accepted: 30 August 2012
The electronic and magnetic properties of a neutral substitutional nickel (Ni0s) impurity in diamond are studied using density functional theory in the generalized gradient approximation. The spin-one ground state consists of two electrons with parallel spins, one located on the nickel ion in a 3d9 configuration and the other distributed among the nearest-neighbor carbons. The exchange interaction between these spins is due to p-d hybridization and is controllable with compressive hydrostatic or uniaxial strain, and for sufficient strain the antiparallel spin configuration becomes the ground state. Hence, the Ni impurity forms a controllable two-electron exchange-coupled system that should be a robust qubit for solid-state quantum information processing.
PACS: 71.55.Cn – Elemental semiconductors / 71.70.Gm – Exchange interactions / 03.67.Lx – Quantum computation architectures and implementations
© EPLA, 2012