Tunable nanoswitches based on nanoparticle meta-molecules

Abstract

We introduce ultra-fast tunable nanoswitches based on the transition between states of nanoparticle meta-molecules. These molecules are formed (activated) when hybrid systems consisting of metallic nanoparticles and semiconductor quantum dots interact with coherent light sources (laser fields). The switching process occurs via minuscule changes of the refractive index of the environment or the distance between the quantum dots and metallic nanoparticles. These changes stimulate the transition between the states of the meta-molecules in nanosecond timescales, setting up dramatic optical events that can be observed easily. These nanoswitches can be tuned by varying the intensity of the activating laser field, allowing us to adjust the switching process to occur at different values of refractive indices. The results open a new horizon for chemically, biologically, or physically triggered optical nanoswitches and nanosensors that are sensitive to ultra-small changes in the environment.

Approaching the quantum limit for nanoplasmonics

“…[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] Descriptions of strongly driven nanohybrids with the emitter treated quantum mechanically and the MNP response treated classically predict a nonlinear Fano effect, bistability, and induced transparency. [31][32][33][34][35][36][37][38] A variety of applications have been proposed that exploit these effects, [46][47][48] suggesting new building blocks for metamaterials with properties very different from those of the constituents of the nanohybrid. Recently, these nanohybrids have been described with a full quantum mechanical treatment with quantized nanoparticle plasmons.…”

Control of excitonic population inversion in a coupled semiconductor quantum dot–metal nanoparticle system

“…In some of these studies, 2,5,7,19 the controlled dynamics of the populations of the ground and single-exciton states of the quantum dot was analyzed, giving emphasis to the influence of the presence of the metal nanoparticle on the population transfer from the ground to the exciton states. Specifically, it has been shown that the period of Rabi oscillations in the quantum dot, which is modeled as a two-level system, is significantly altered due to the presence of the plasmonic nanoparticle.…”

“…Specifically, it has been shown that the period of Rabi oscillations in the quantum dot, which is modeled as a two-level system, is significantly altered due to the presence of the plasmonic nanoparticle. 2,7 In addition, Sadeghi showed that the Rabi oscillations can be destroyed for certain interparticle distances due to the rise of plasmonic metaresonances. 5 More recently, Antón et al 19 showed that if the quantum dot is modeled as a three-level V-type system, then selective excitonic population transfer can be achieved due to the presence of the plasmonic nanoparticle.…”

Investigation of coherent molecular resonances in quantum dot–metallic nanoparticle systems using their spontaneous emission

“…Here μ 12 refers to the dipole moment of the 1-2 transition and E QD to the effective field experienced by the QD given by [55,30] Here Ω 0 12 ¼ Àμ 12 E 0 =2ℏε eff 1 is Rabi frequency of the QD when is isolated. Δ eff ¼ ℏω n 12 À ℏω l is the effective detuning of the laser field, wherein ℏω n 12 refers to the energy of the 1-2 transition renormalized by coherent-plasmonic effects, given by ℏω n 12 ðω l ; I l Þ ¼ ℏω 12 …”