Few-qubit quantum-classical simulation of strongly correlated lattice   fermions
  We study a proof-of-principle example of the recently proposed hybrid quantum-classical simulation of strongly correlated fermion models in the thermodynamic limit. In a "two-site" dynamical mean-field theory (DMFT) approach we reduce the Hubbard model to an effective impurity model subject to self-consistency conditions. The resulting minimal two-site representation of the non-linear hybrid setup involves four qubits implementing the impurity problem, plus an ancilla qubit on which all measurements are performed. We outline a possible implementation with superconducting circuits feasible with near-future technology. 
Juha M Kreula, Laura Garc\'ia-\'Alvarez, Lucas Lamata, Stephen R   Clark, Enrique Solano, and Dieter Jaksch
quant-ph cond-mat.mes-hall cond-mat.supr-con