A tunable bistable device based on a coupled quantum dot–metallic nanoparticle nanosystem

Abstract

nonlinear [9], and a planar metamaterial with broken structural symmetry on a nonlinear substrate [10]. The bistable optical response in these nanostructures commonly occurs under a relatively strong light illumination or by assisting with some large nonlinearity. Very luckily, metal-semiconductor hybrid nanostructures, which are expected to overcome those weaknesses in metal nanostructures, have been synthesized and provided a new way to explore the physical mechanism of optical bistability via the interaction between excitons in semiconductors and plasmons in metal nanostructures.The exciton-plasmon interaction can significantly modify the optical properties of metal-semiconductor hybrid nanosystems, such as nonlinear Fano effect [11], coherent molecular resonances [12], electromagnetically induced transparency [13], energy transfer [14, 15], slow light effect [16, 17], superradiance [18], enhanced thirdorder nonlinear optical response [19], intensity-dependent enhancement of saturable absorption [20], enhancement of the second-harmonic generation [21], strongly modified four-wave mixing, and four-wave parametric amplification [22, 23]. To date, some inspiring results around optical bistability have been achieved, showing that an optical bistability regime occurs as the coupling between semiconductor quantum dot (SQD) and metal nanoparticle (MNP) becomes stronger by increasing the sizes of both SQD and MNP [24]. Then, Malyshev et al. [25] reported that a coupled SQD-MNP nanosystem could manifest bistability by measuring optical hysteresis of the Rayleigh scattering. Malyshev also derived the analytical bistability condition and the exact steady-state solution of the Bloch equations at the absolute bistability threshold in the similar system [26]. Recently, Knoester et al. [27] explored the switching times from the lower stable branch to the upper stable one. In our previous work, we revealed the bistable properties Abstract We theoretically propose a scheme of a tunable bistable device based on a coupled semiconductor quantum dot-metal nanoparticle nanosystem in the simultaneous presence of a strong pump laser and a weak probe laser with different frequencies. The results show that it is easy to turn on or off the optical bistable effect in such system by switching the polarization direction of the pump field, and the bistability thresholds are highly sensitive to the intensity, frequency, polarization direction of the pump field, and the interparticle distance. In addition, the nonlinear absorption in the two stable states exhibits a ratio as high as 10 4 arising from the three-photon effect, which implies that our nanosystem can also be used as an optical memory cell.

Control of Self-Kerr Nonlinearity in a Driven Coupled Semiconductor Quantum Dot–Metal Nanoparticle Structure

“…The optical effects that are induced fall within quantum plasmonics, a relatively new area of nanophotonics. These effects include enhanced emission, , induction of Rabi oscillations with tunable period and controlled population transfer, − formation of Fano-type absorption features, − tunable gain without inversion, − plasmonically induced optical transparency accompanied with slow light, − significantly modified four-wave mixing, − four-wave parametric amplification, and self-Kerr nonlinearity. − …”

“…The most extensively studied nanostructure in this research area is composed of a SQD, which is modeled by a two-level quantum system, and a spherical MNP. ,− ,− ,,− , The interaction of this hybrid system with a weak probe field of varying frequency and a strong pump field of fixed frequency has been the subject of several studies, ,,,− and the phenomena that have been investigated include the pump-controlled probe absorption and dispersion of the structure, ,, as well as the study of cross-Kerr nonlinearity − that leads to four-wave mixing , and four-wave parametric amplification . In addition, the strong plasmonically induced modification of self-Kerr nonlinearity of a weak probe field in a coupled SQD–MNP structure has been only considered either in a two-level SQD without the application of the pump field or in three-level and four-level models of the SQDs that exhibit vacuum-induced transparency due to the presence of the plasmonic nanostructure, combined electromagnetically induced transparency effects and plasmonically induced effects, − or even combined vacuum-induced transparency and electromagnetically induced transparency near a plasmonic nanostructure .…”

Optical bistability of a plexcitonic system consisting of a quantum dot near a metallic nanorod

“…Four-wave mixing (FWM) response and optical bistability (OB) in a hybrid nanosystem composed of a metal nanoparticle (MNP) and a semiconductor quantum dot (SQD) coupled to a nanomechanical resonator are investigated theoretically [18]. Optical properties of a complex system including a closely spaced spherical SQD and a metal nanosphere were investigated [19]. It was shown that the system can manifest bistability and optical hysteresis [20].…”

Fano resonances and slow light in a nanocavity assisted by metallic nanoparticles‐quantum dot system

“…Meanwhile, semiconductor QD-MNP molecules which comprise the strongly coupled excitons and plasmons therein, demonstrate many novel properties such as Fano effect [44,[79][80][81], coherent population oscillation [82], plasmonic electromagnetically induced transparency [83,84]. Nanoswitch [85] and optical memory cell [86] have been put forward based on QD-MNP hybrid system and the system dispersion and absorption strongly depend on the QD material parameters [87][88][89][90]. It is reviewed that QD and MNP can couple from weakly to strongly, showing different distinctive optical properties [91].…”