2 research outputs found
Controlled unidirectional reflectionlessness by coupling strength in a non-Hermitian waveguide quantum electrodynamics system
Unidirectional reflectionlessness is investigated in a waveguide quantum
electrodynamics system that consists of a cavity and a -type
three-level quantum dot coupled to a one-dimensional plasmonic waveguide.
Analytical expressions of transmission and reflection coefficients are derived
and discussed for both resonant and off-resonant couplings. By appropriately
modulating the coupling strength, phase shift and Rabi frequency,
unidirectional reflectionlessness is observed at the exceptional points. And
unidirectional coherent perfect absorption is exhibited at the vicinity of
exceptional point. These results might find applications in designing quantum
devices of photons, such as optical switches and single-photon transistors.Comment: 11 pages, 7 figure
Nonreciprocal photon transport in indirectly coupled whispering-gallery mode resonators
We study the reflection and transmission properties of a system comprising
two whispering-gallery mode resonators, each containing a Zeeman-split quantum
dot and side-coupled to an optical fiber. Our results demonstrate that
unidirectional reflection and transmission can be achieved by tuning the
coupling strength between the resonators and the optical fiber. Furthermore, we
establish a correspondence between quantum dot energy level resonance
frequencies and the positions of low reflection (transmission) peaks at a phase
shift of {\pi}. This research provides insights for the development of quantum
optical devices like isolators, circulators, and routers.Comment: 9 pages, 6 figures, 47 reference