Physical review. B, Condensed matter
Theory of a type of quantum amplification: Phase-sensitive amplification by frequency upconversion
F. F. Popescu
Abstract
It is shown that the spectroscopic bridge, a recently proposed method to achieve high-efficiency microwave oscillators and phase-sensitive detectors, may be used in a spin multiplet of certain paramagnetic ions to obtain a type of microwave quantum amplification: phase-sensitive amplification by frequency upconversion. This operation of a solid-state maser without population inversion is based on a principle similar to that used for achieving amplification in a transistor (triode). The major differences between this amplification and the parametric amplification, or the usual double-resonance maser action, are discussed.