Enhanced photon drag in closed-loop quantum systems

Abstract

In recent years, photon drag has attracted enormous attention owing to both fundamental and practical interests. In this paper, we investigate dragging effect in quantum systems with closed-loop interaction. First, we demonstrate an enhanced photon drag in a moving atomic medium with a three-level Λ-type structure. By incorporating the interference of spontaneous emissions, the properties of the atomic medium can be easily controlled by the relative phase of applied fields so that a large group index along with a transparency or even a gain can be achieved. As the photon drag is proportional to the group index, the enhancement can be also found in the dragging of light. Such enhanced dragging effect can be applied for the efficient modulators of light, position control, and the detection of slow motion. We then investigate the Fresnel’s light drag effect in another closed-loop structure, i.e. chiral molecules with a cyclic three-level Δ-type configuration, and show that left- and right-handed chiral molecules exhibit different dragging effects. This provides a possible way to probe the molecular chirality, which may find applications in the sorting and separation of chiral molecules.

Dispersion-dependent superluminal propagation and photon drag in GaAs/AlGaAs quantum dot molecule

“…For example, the purple curve in the plot shows subluminal propagation while the green and blue curves demonstarte superluminal light propagation. As can be seen, the rotation of light polarisation states in superluminal and subluminal regimes occur opposite and along medium motion, respectively, which are consistent with previous investigations [21,23,24,28,29,31]. In other words, based on signs of photon drag against translational and rotational velocity of medium, one can determine whether light propagation is subluminal or superluminal.…”

“…Experimental demonstration of longitudinal light drag in rubidium vapours was reported by Safari et al [20]. Kazemi and Mahmoudi [21] achieved a significant enhancement in photon-drag in a three-level chiral and non-chiral atomic optical medium. Qin et al [22] reported light drag enhancement by a factor of ~10 4 in fast-and slow-light medium in a moving microcavity.…”

Sagnac interferometry and the impact of conductivity-dependent Raman gain on rotary photon drag

“…Other investigations have explored RPD using various setups, such as a gain-assisted N-type atomic system [12] and rotary chiral media with unusual refraction [13]. Additionally, an enhancement in RPD was achieved using a closed-loop quantum system with a large group index [14]. Consequently, experimental and theoretical investigations of RPD have been pursued, employing various techniques [15][16][17][18][19].…”

Chirality-dependent optical dipole potential

“…Based on this kind of transition structure, some optical methods for enantioseparation, e.g. cyclic population transfer [13,14] and dynamical control [15], as well as probing molecular chirality [16][17][18] have been suggested. The idea was to couple chiral molecules, with a cyclic three-level Δ-configuration structure, to three optical fields in such a way that one-and two-photon processes can coexist.…”