Single-photon scattering controlled by an imperfect cavity

We study the single-photon transport in the coupled-resonator waveguide (CRW) controlled by an imperfect cavity. A Lorentzian spectrum is introduced to describe the dissipation. We find that the probability current conservation can be broken, although the imperfect cavity is a Hermitian system. The coupling strength between the imperfect cavity and the CRW has significant influences near the resonant frequency. With the increase of the coupling strength, the transmission coefficient becomes smaller. The spectral width plays a dominant role under the off-resonant condition, where the transmission coefficient is greatly suppressed with the increase of the spectral width. We also observe an abrupt jump of the transmission and reflection coefficients when the hopping amplitude is large enough. All the distinctive behaviors are closely related to the complex effective potential induced by the imperfect cavity

Membrane-Mediated Interactions between Nanoparticles on a Substrate

Investigations of the interactions between nanoparticles and lipid bilayer may yield insight into the understanding of the protein−biomembrane interactions and the cytotoxicity of drugs. Here, we theoretically investigate the membrane-mediated interactions between two nanoparticles supported on a substrate. We examine the effects of the packing density of lipids, the direct nanoparticle−lipid interaction, and the direct substrate−lipid interaction on the effective interactions between the nanoparticles and find the effective interactions between the two nanoparticles are mainly dominated by the competition of the deformations of the different parts of the lipid bilayers as well as the stretching of the lipid chains sandwiched between the nanoparticles. By varying the above-mentioned effects, the effective interactions between the two nanoparticles can be efficiently modulated. The results may provide some theoretical insight into experiments on the membrane-mediated nanoparticle organization on a substrate and organization of the membrane proteins or drug nanoparticles on the surfaces of the cellular membranes