Plasmonic (thermal) electromagnetically induced transparency in metallic nanoparticle-quantum dot hybrid systems

Energy absorbed from double quantum dot-metal nanoparticle hybrid system

This work proposes the double quantum dot (DQD)-metal nanoparticle (MNP) hybrid system for a high energy absorption rate. The structure is modeled using density matrix equations that consider the interaction between excitons and surface plasmons. The wetting layer (WL)-DQD transitions are considered, and the orthogonalized plane wave (OPW) between these transitions is considered. The DQD energy states and momentum calculations with OPW are the figure of merit recognizing this DQD-MNP work. The results show that at the high pump and probe application, the total absorption rate [Formula: see text] of the DQD-MNP hybrid system is increased by reducing the distance between DQD-MNP. The high [Formula: see text] obtained may relate to two reasons: first, the WL washes out modes other than the condensated main mode. Second, the high flexibility of manipulating DQD states compared to QD states results in more optical properties for DQD. The [Formula: see text] is increased at a small MNP radius on the contrary to the [Formula: see text] which is increased at a wider MNP radius. Under high tunneling, a broader blue shift in the [Formula: see text] due to the destructive interference between fields is seen and the synchronization between [Formula: see text] and [Formula: see text] is destroyed. [Formula: see text] for the DQD-MNP is increased by six orders while [Formula: see text] is by eight orders compared to the single QD-MNP hybrid system. The high absorption rate of the DQD-MNP hybrid system comes from the transition possibilities and flexibility of choosing the transitions in the DQD system, which strengthens the transitions and increases the linear and nonlinear optical properties. This will make the DQD-MNP hybrid systems preferable to QD-MNP systems.

The Intensity of the Plasmon–exciton of Three Spherical Metal Nanoparticles On the Semiconductor Quantum Dot Having Three External Fields

The influence of the plasmon of three spherical metal nanoparticles (MNPs) on the semiconductor quantum dot (SQD) having three external fields is analyzed. The density matrix equations are modified for the description of the optical properties of the SQD-MNPs nanosystem. We study theoretically the role of the plasmon–exciton dipole coupling in the SQD-MNPs nanosystem. We investigate the dependence of the plasmon–exciton dipole coupling of the SQD-MNPs nanosystem on the position of three spherical MNPs with respect to SQD as well as on the material parameters of the hybrid nanosystem. The direction and detunings of the three external fields play an important role in the characterization of the SQD-MNPs nanosystem.

Analysis and Simulation of the Optical Properties of a Quantum Dot on a Graphene Nanoribbon System

In this work, we theoretically study the optical properties of a graphene nanoribbon with a quantum dot (QD) on it. The system consists of a graphene nanoribbon with dimensions of 400 × 3100 (nm2) and a quantum dot with a nanoscale radius. The quantum dot is symmetrically located at the center of the graphene nanoribbon to simplify the mathematical model. To calculate the optical properties (susceptibility) of the system, a broadband electromagnetic wave (0.5–2.5 μm) is applied to the structure to model dipole-dipole interaction. Considering the input field and calculating the total induced polarization, the optical susceptibility of the system is calculated. The applied electromagnetic field excites the surface plasmon on the graphene nanoribbon and the excitons of QDs. The induced dipoles in the graphene nanoribbon and the QD will interact with each other. We show that the parameters of both materials strongly influence dipole-dipole interaction. In particular, the effect of QDs (location on graphene and radius) on the optical properties of the considered system was studied. The obtained results can be used to introduce periodic optical structures in nanoscale by inserting QDs in a periodic array on graphene nanoribbon. Additionally, applications such as reflectors, couplers, and wavelength filters can be designed. Considering the presented theoretical framework, we can describe all the optoelectronic and optomechanical applications of complex nanoscale graphene and QD systems.

Highly efficient vortex four-wave mixing in asymmetric semiconductor quantum wells

Orbital angular momentum (OAM) is an important property of vortex light, which provides a valuable tool to manipulate the light-matter interaction in the study of classical and quantum optics. Here we propose a scheme to generate vortex light fields via four-wave mixing (FWM) in asymmetric semiconductor quantum wells. By tailoring the probe-field and control-field detunings, we can effectively manipulate the helical phase and intensity of the FWM field. Particularly, when probe field and control field have identical detuning, we find that both the absorption and phase twist of the generated FWM field are significantly suppressed. Consequently, the highly efficient vortex FWM is realized, where the maximum conversion efficiency reaches around 50%. Our study provides a tool to transfer vortex wavefronts from input to output fields in an efficient way, which may find potential applications in solid-state quantum optics and quantum information processing.

Application of Metallic Nanomaterials in Nanomedicine

In this chapter, we explain why metallic nanomaterials are used in nanomedicine. We have shown that the electron density in metallic nanomaterials oscillates and creates electron density waves. When laser light falls on metallic nanoparticles, light interacts with electron density waves. According to Einstein, light, which is electromagnetic waves, consists of particles called photons. Similarly, electron density waves are also made of particles called surface plasmons. Therefore, photons from laser light and surface plasmons from metallic nanostructures interact with each other and create new particles called surface plasmon polaritons. These new particles produce an intense light near the surface of metallic nanomaterials. We showed that this intense light is important in the application of metallic nanomaterials in nanomedicine. Further, we have applied metallic nanoparticles, single metallic nanoshells and double metallic nanoshells for treatment of cancer and detection of smaller tumors.

Electromagnetically induced holographic imaging in hybrid artificial molecule

We propose two schemes of holographic imaging with an object that has no any macro structure itself. The tunable electromagnetically induced grating (EIG) is such a kind of object. We obtain an EIG based on the periodically modulated strong susceptibility in a three-level ladder-type hybrid artificial molecule, which is comprised of a semiconductor quantum dot and a metal nanoparticle coupled via the Coulomb interaction. The holographic interference pattern is detected either directly in the way of classical holographic imaging with a coherent field being the imaging light, or indirectly and nonlocally in the way of two-photon coincidence measurement with a pair of entangled photons playing the role of imaging light. This work provides a practical prototype of electromagnetically induced transparency-based holographic solid-state devices for all-optical classical and quantum information processing.

Photoinduced diffraction grating in hybrid artificial molecule

Photoinduced diffraction grating is theoretically investigated in a three-level ladder-type hybrid artificial molecule comprised of a semiconductor quantum dot (SQD) and a metal nanoparticle (MNP). The SQD and the MNP are coupled via the Coulomb interaction. The probe absorption vanishes under the action of a strong coupling field, indicating an effect of electromagnetically induced transparency (EIT). Based on this EIT effect, diffraction grating is achievable when a standing-wave coupling field is applied. It turns out that the efficiency of diffraction grating is greatly improved due to the existence of the MNP. Furthermore, the diffraction efficiency can be controlled by tuning the interaction strength between the SQD and the MNP. Nearly pure phase grating is obtained, showing high transmissivity and high diffraction efficiency up to 33%.