We carry out a theoretical study on optical bistability of near field intensity and transmittance in two-dimensional nonlinear composite slab. This kind of 2D composite is composed of nonlocal metal/Kerr-type dielectric core-shell inclusions randomly embedded in the host medium, and we derivate the nonlinear relation between the field intensity in the shell of inclusions and the incident field intensity with self-consistent mean field approximation. Numerical demonstration has been performed to show the viable parameter space for the bistable near field. We show that nonlocality can provide broader region in geometric parameter space for bistable near field as well as bistable transmittance of the nonlocal composite slab compared to local case. Furthermore, we investigate the bistable transmittance in wavelength spectrum, and find that besides the input intensity, the wavelength operation could as well make the transmittance jump from a high value to a low one. This kind of self-tunable nano-composite slab might have potential application in optical switching devices.

Measuring the nonlocality of different types of Majorana bound states in a topological superconducting wire.

With the self-consistent mean-field method in the framework of full-wave nonlocal scattering theory, we theoretically investigate the optical bistability in a nonlocal metallic nanocylinder coated with Kerr-type nonlinear shell. A nonlocality enhanced Fano profile is found for this coated cylinder in the linear limit. We illustrate the relation between the linear plasmonic resonant wavelength and the viable parameters for optical bistability in parameter space. It is found that nonlocality will lead to impressive blue shift of the resonant wavelength, and hence dramatically increase the bistable region in the parameter space of incident wavelength and geometrical factor. We demonstrate the input-field-controllable and input-wavelength-controllable scatterings in the nonlinear case, respectively. It indicates that nonlocal effects show opposite influences on these two nonlinear scattering processes, and the bistability in the scattering spectrum is weaken by nonlocality. Our study reveals that these self-tunable optical resonant scatters can be used as all-optical switches and might provide flexible possibilities in the design of optical bitable devices.

We study nonequilibrium (NE) transport in four-terminal (three-terminal) topological superconductor (SC)-quantum dot (QD) topological superconductor junctions, where the QD is connected via tunneling barriers to the two TS leads and two (one) normal leads (N), respectively. For the four-terminal junction, we find that when increasing the Zeeman field from 0 to a critical value, the supercurrent profile evolves from a typical s-wave pattern to a pure p-wave pattern. In addition, by analyzing the zero-phase difference supercurrent as a function of voltage [Formula: see text] applied to the normal leads and the Zeeman field h applied to the SC, the low-momentum gap [Formula: see text] can be inferred by utilizing the fact that the emergence of a tunneling-induced current should be satisfied under the condition [Formula: see text]. For the three-terminal junction, the NE supercurrent can reveal the quasi-Andreev bound state by exploiting the Andreev reflection process-induced current occurring between the N and SC. Our findings provide an arguably easier route for manifesting the topological phase transition by observing the gap collapse and then reopening as the Zeeman field increases through multi-terminal NE transport.

No abstract