Tunable single-photon diode by chiral quantum physics
Wei‐Bin Yan, Weiyuan Ni, Jing Zhang, Feng‐Yang Zhang, Heng Fan · Physical Review A · 2018
We investigate a single-photon diode realized by a one-dimensional waveguide chirally coupled to $N$ spatially separated $\mathrm{\ensuremath{\Lambda}}$-type three-level emitters. An external laser is introduced to drive the emitters. The single photons moving in opposite directions show different transmission probabilities, which underpins the diode behavior. In the case of a single emitter, the single-photon diode works well at specific frequency points, which are tunable by the external laser. In the case of multiple emitters, the optimal-working-frequency point of the diode can be turned to a broad band.