Coherent repopulating hyperfine-structure levels by pulsed resonance fields and the quantum computer problem

A new method of polarization of atoms and nuclei by pulsed bichromatic resonance radio-frequency fields is proposed to produce an initial state of a quantum computer constructed with the use of cubits representing impurity atoms in a solid matrix having the hyperfine structure. It is shown that this method can provide strong polarization without using ultralow temperatures. The problem is considered for the interaction of three-and four-level systems with bichromatic and two-phase fields.