Gain without inversion in hybrid quantum dot–metallic nanoparticle systems

Abstract

We study the generation of tunable gain without inversion in semiconductor quantum dots using plasmonic effects. For this we investigate the impact of localized surface plasmons on coherent nonlinear exciton effects in a quantum dot when it is located in the vicinity of a metallic nanoparticle. It is shown that when such a system is exposed to a laser field and the distance between the quantum dot and the metallic nanoparticle is reduced the initial impact of plasmons is enhancement of the ac-Stark shift in the quantum dot. When this distance is reduced beyond a critical value, the results show abrupt formation of a significant of amount of gain without inversion in the quantum dot. We show that such a 'molecular' gain is associated with the plasmonic metaresonance (PMR) formed via combined effects of laser-induced coherence in the quantum dot and plasmons.

Condition for resonant optical bistability

“…The local-field correction leads to a self-action of the system, which results in a nonlinear relation between the applied field and the one acting on the system. This type of OB mechanism can be relevant for a large variety of systems: dense 3D assemblies of two-level atoms [9,14], optically dense thin films of TLS [24,25] and films of linear molecular aggregates [26][27][28], hybrid metal-semiconductor systems [20][21][22][23], and a more general case of a TLS in an environment involving dielectric and conducting surfaces, such as a stratified medium, a microcavity, or a nanostructure.OB can occur within a range of internal system parameters and external-field intensities; identifying these ranges is therefore an important problem and its analytical solution is desirable. To the best of the author's knowledge, so far * on leave from A. F. Ioffe Physical-Technical Institute, 194021 St. Petersburg, Russia; a.malyshev@fis.ucm.es.…”

“…Besides, the question of OB and hysteresis has received renewed attention in connection with novel hybrid zero-dimensional (0D) nanoscopic systems, e.g., artificial molecules comprising a semiconductor quantum dot (SQD) and metal nanoparticles (see Refs. [20][21][22][23] and references therein).…”

Quadratic Electro-Optic Effect and Electro Absorption Process of Multi-layer Spherical Quantum Dot Enhanced by Metal Nanoparticle

“…In recent years, the interaction of quantum dots and metal nanoparticles (MNP) have been one of the most important subjects studied in hybrid structure [23][24][25][26][27][28] because the MNP strengthens the local field felt by the QD, which may enhance emission and luminescence [29]. Hybrid QD-MNP systems have been used for ultrahigh optical absorption and low electrical resistance at optoelectronic interfaces [30] and detect the possible signature of Majorana fermions [31], coherent controllable transport of a plasmonic waveguide [32], colorimetric measurements of DNA conjugations [33,34], laser systems without cavities [35][36][37], manipulation of heat generation in MPs [38,39], energy transfer processes in superstructures formed via bio-molecules [40], etc. Plasmonic field enhancement via MNPs has also been used for various device applications such as optical and plasmonic antennas [41][42][43][44], quantum nanosensor [45], nonlinear switching [46], and light emitting devices [47].…”

Pump-probe optical response of an asymmetric double quantum dot molecule

“…In parallel, the nonlinear optical response of semiconductor quantum wells [19][20][21][22][23][24][25][26] and semiconductor quantum dots [27][28][29][30][31][32][33][34][35] that interact simultaneously with a strong pump field and a weak probe field has also been studied and phenomena such as controlled absorption and optical transparency, the ac-Stark effect, optical gain, enhanced selfKerr nonlinearity with low absorption, enhanced four-wave mixing and even slow light have been shown. We note that the subject of the interaction of a quantum (atomic) system simultaneously driven by a strong pump field and a weak probe field started by Mollow more than 40 years ago [36] and was extended by several others [37][38][39][40][41][42][43][44][45].…”

“…Also, Xu et al [28] investigated the optical response of a singly charged quantum dot under a strong optical driving field by probing the system with a weak optical field and found controlled absorption, the ac-Stark effect, and optical gain. In addition, the interaction of semiconductor quantum dots coupled to a metallic nanosphere with a strong pump field and a weak probe field has been investigated in detail recently [29][30][31][32][33][34][35]. Moreover, an initial study of the gain spectrum of a strongly-driven asymmetric double quantum dot molecule has been presented in Ref.…”