Optical bistability and hysteresis of hybrid metal-semiconductor nano-dimer

TL;DR

This paper theoretically investigates optical bistability and hysteresis in a hybrid nano-dimer composed of a semiconductor quantum dot and a metal nanoparticle, highlighting potential applications in nanoscale optical memory.

Contribution

It demonstrates that internal degrees of freedom in a semiconductor-metal nano-dimer can produce observable optical bistability and hysteresis effects, which were not previously characterized in such systems.

Findings

Optical bistability and hysteresis can occur in hybrid nano-dimers.

These effects are observable in real systems like CdSe quantum dots with Au nanoparticles.

The system's dipole moment can switch abruptly, enabling potential optical memory applications.

Abstract

Optical response of an artificial composite nano-dimer comprising a semiconductor quantum dot and a metal nanosphere is analyzed theoretically. We show that internal degrees of freedom of the system can manifest bistability and optical hysteresis as functions of the incident field intensity. We argue that these effects can be observed for the real world systems, such as a CdSe quantum dot and an Au nanoparticle hybrids. These properties can be revealed by measuring the optical hysteresis of the Rayleigh scattering. We show also that the total dipole moment of the system can be switched abruptly between its two stable states by small changes in the excitation intensity. The latter promises various applications in the field of all-optical processing at nanoscale, the most underlying of them being the volatile optical memory.