Modelling of quantum information processing with Ehrenfest guided tra jectories: a case study

We apply a numerical method based on multi-configurational Ehrenfest tra jectories, and demonstrate converged results for the Choi fidelity of an entangling quantum gate between two two-level systems interacting through a set of bosonic modes. We consider both spin-boson and rotating wave Hamiltonians, for various numbers of mediating modes (from 1 to 100), and extend our treatment to include finite temperatures. Our results apply to two-level impurities interacting with the same band of a photonic crystal, or to two distant ions interacting with the same set of motional degrees of freedom.