Four atomic optical energy levels as a two-qubit quantum computer register

摘要

Four atomic optical energy levels is proposed to use as a two qubit quantum register. A single Pr$+3$PLU$/ atom in a monocrystal LaF$-3$/ subjected to resonant laser irradiation is used as an example to illustrate the implementation of the universal set of quantum gates. This physical system equilibrium state is a desirable input state for quantum computation and therefore there is no need for its special preparation procedure.