Single-qubit operations in the double-donor structure driven by strongly detuned optical pulses

Abstract

We study theoretically the quantum dynamics of an electron in the singly-ionized double-donor structure in the semiconductor host under the influence of two strongly detuned laser pulses. This structure can be used as a charge qubit where the logical states are defined by the lowest two energy states of the remaining valence electron localized around one or another donor. The quantum operations are performed via Raman-like transitions between the localized (qubit) states and the manyfold of states delocalized over the structure. The possibility of realization of arbitrary single-qubit rotations, including the phase gate, the NOT gate, and the Hadamard gate, is demonstrated. The advantages of the off-resonant driving scheme for charge qubit manipulations are discussed in comparison with the resonant scheme proposed earlier.