Single-qubit gates for ensemble qubits via off-resonant Raman interaction

In this paper we analyze the fidelity of single-qubit gates based on off-resonant Raman interaction when they are applied to qubits implemented as ensembles of active centers. In particular, we investigate the additional errors induced by the inhomogeneous broadening of the qubit ensemble. We propose a new scheme which can be used to significantly decrease these errors and to realize high-fidelity logic gates for ensemble qubits.