Nonreciprocal transition between two nondegenerate energy levels

Abstract

Stimulated emission and absorption are two fundamental processes of light-matter interaction, and the coefficients of the two processes should be equal in general. However, we will describe a generic method to realize significant difference between the stimulated emission and absorption coefficients of two nondegenerate energy levels, which we refer to as nonreciprocal transition. As a simple implementation, a cyclic three-level atom system, comprising two nondegenerate energy levels and one auxiliary energy level, is employed to show nonreciprocal transition via a combination of synthetic magnetism and reservoir engineering. Moreover, a single-photon nonreciprocal transporter is proposed using two one dimensional semi-infinite coupled-resonator waveguides connected by an atom with nonreciprocal transition effect. Our work opens up a route to design atom-mediated nonreciprocal devices in a wide range of physical systems.

Enantiomeric excess determination based on nonreciprocal transition induced spectral line elimination

“…The population can transfer from the level |b to level |a for Φ = 3π/2, but almost no population will transfer from the level |b to level |a when Φ = π/2, which agrees with the re-sult given in Ref. [6]. It has been shown in Ref.…”

“…It has been shown in Ref. [6] that the transition probability for |b → |a is different from the one for |a → |b when Φ = nπ (n is an integer), i.e., the transitions between levels |b and |a are nonreciprocal. As the decay induced coupling terms with p σσ ′ √ γσγ σ ′ 2 e ±iω σσ ′ t ) in Eqs.…”

“…Nonreciprocity means that some particles or waves exhibit different transmission properties when their sources and detectors are exchanged, such as the one-way electric conduction in the semiconductor p-n junctions. In a recent paper [6], some of us introduced the concept of nonreciprocity to investigate the transitions between different energy levels, and proposed a generic method to realize significant difference between the stimulated emission and absorption coefficients of two nondegenerate energy levels, which we refer to as nonreciprocal transition [6]. The nonreciprocal transition can be used for many applications, such as single-photon nonreciprocal transporter [6], nonreciprocal phonon devices [7,8], and the echo cancellation in quantum memory [9] and quantum measurements [10].…”