Long-range quantum gates using dipolar crystals
  We propose the use of dipolar spin chains to enable long-range quantum logic between distant qubits. In our approach, an effective interaction between remote qubits is achieved by adiabatically following the ground state of the dipolar chain across the paramagnet to crystal phase transition. We demonstrate that the proposed quantum gate is particularly robust against disorder and derive scaling relations, showing that high-fidelity qubit coupling is possible in the presence of realistic imperfections. Possible experimental implementations in systems ranging from ultracold Rydberg atoms to arrays of Nitrogen-Vacancy defect centers in diamond are discussed. 
Hendrik Weimer, Norman Y. Yao, Chris R. Laumann, Mikhail D. Lukin
quant-ph cond-mat.mes-hall