Quantum information processing based on P-31 nuclear spin qubits in a   quasi-one-dimensional Si-28 nanowire
  We suggest a new method of quantum information processing based on the precise placing of P-31 isotope atoms in a quasi-one-dimensional Si-28 nanowire using isotope engineering and neutron-transmutation doping of the grown structures. In our structure, interqubit entanglement is based on the indirect interaction of P-31 nuclear spins with electrons localized in a nanowire. This allows one to control the coupling between distant qubits and between qubits separated by non-qubit neighboring nodes. The suggested method enables one to fabricate structures using present-day nanolithography. Numerical estimates show the feasibility of the proposed device and method of operation. 
Issai Shlimak and Israel Vagner