Near-infrared switching between slow and fast light in the metal nanoparticles-graphene nanodisks-quantum dots hybrid systems

Abstract

Graphene-based nanocomposites have recently attracted much interest due to the unique properties of graphene plasmons paving the way to promising potential applications. We study the near-infrared linear optical properties of the metal nanoparticle-graphene nanodisk- quantum dot hybrid system by numerically solving the equation of motion for the density matrix elements that describe the dynamics of the system where the quantum dot is modeled as a three-level atomic system of Λ configuration interacting with a weak probe field and strong control field. We obtain a strong switching between slow and fast light near resonance can be controlled by the distances between the components of the system, the size of metal nanoparticle as well as the Rabi frequency of the control field. Moreover, the proposed hybrid plasmonic system shows a significant amplification without population inversion can be effectively monitored by strength of the control field. Thus, we think that the metal nanoparticle-graphene nanodisk- quantum dot hybrid system has potential applications in communication, sensing, imaging, signal processing and optoelectronics devices.

Tunable Switching between Slow and Fast Light in the Double Metal Nanoparticles (MNPs)-Quantum Dot (QD) Plasmonic Hybrid Systems

“…The QD's atomic density is set as [41], the dielectric constant ǫ q = 6.9, dipole moments of µ 12 =µ 13 =1enm [19,41], and the decay rates are set as γ 12 =γ 13 =1GHz [41] and γ 32 =0.3γ 12 [42]. The strength of the probe field is Ω p =0.01Ω c [33].…”

“…This result is reasonable since silver MNP is chosen to be resonant with QD and it is desirable to decrease its separation distance from QD to enhance DDI. Since a plasmonic particle's polarizability depends on its size, and in such systems like semiconductor quantum dots(QD)-graphene nanodisk(GND)-metal nanoparticle(MNP) hybrid systems, it has been shown that the switching between slow and fast light can be adjusted by changing the size of the MNP [33], Figure 3 shows how the silver MNP can be used to adjust the switching between slow and fast light of the probe field. We notice that the group index is significantly influenced by the radius of the silver MNP (R Ag ).…”

“…In addition, the optical properties of complex nanomaterials that combine metal and graphene have attracted significant interest in developing nanoscale optoelectronic devices, which enhance light-matter interaction. The linear optical properties in metal nanoparticle-graphene nanodisk-quantum dot hybrid systems have been examined [32,33]. It has been found that these linear properties can be controlled by the geometrical features of the system and the interacting fields.…”