Projected equations of motion approach to hybrid quantum/classical dynamics in dielectric-metal composites

Abstract

Grüning, M. (2016)We introduce a hybrid method for dielectric-metal composites that describes the dynamics of the metallic system classically whilst retaining a quantum description of the dielectric. The timedependent dipole moment of the classical system is mimicked by the introduction of projected equations of motion (PEOM) and the coupling between the two systems is achieved through an effective dipole-dipole interaction. To benchmark this method, we model a test system (semiconducting quantum dot-metal nanoparticle hybrid). We begin by examining the energy absorption rate, showing agreement between the PEOM method and the analytical rotating wave approximation (RWA) solution. We then investigate population inversion and show that the PEOM method provides an accurate model for the interaction under ultrashort pulse excitation where the traditional RWA breaks down.

Nonlinear optical rectification and optical bistability in a coupled asymmetric quantum dot-metal nanoparticle hybrid

“…The closeness of the steady-state population difference achieved for the polar and non-polar hybrid system allows one to justify the approximations made to reach Eq. (15).…”

“…1,2 A prototype system to observe these effects comprises a semiconductor quantum dot (QD) and a spherical MNP. Several interesting optical effects have been studied in this hybrid nanostructure, including Fano-type phenomena in absorption of energy, [3][4][5][6][7] controlled coherent population transfer and ultrafast switching, [8][9][10][11][12][13][14][15] gain without inversion, [16][17][18][19] controlled optical bistability, 20-23 strongly modified resonance fluorescence, 18,[24][25][26][27][28][29][30] and four-wave mixing, [31][32][33][34] as well as plasmon-enhanced difference-frequency generation, 35 second-harmonic generation, 36,37 terahertz emission, 38 and Kerr nonlinearity. 39 Besides on-chip nanoscale photonic nonlinear devices, the coupled QD-MNP system may also have important applications in quantum technology, 40,41 sensing, 42 and medicine.…”

Efficient Biexciton Preparation in a Quantum Dot—Metal Nanoparticle System Using On-Off Pulses

“…An active research topic within the field of quantum plasmonics [ 1 , 2 ] is the efficient population control of the exciton and biexciton states in semiconductor quantum dots (SQD) closely placed to metallic nanoparticles (MNP) [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. For these hybrid nanostructures the population dynamics is rather different compared to the case of a single SQD, since the presence of the MNP amplifies the external electric field and induces interaction between SQD excitons and localized surface plasmons [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”

“…For these hybrid nanostructures the population dynamics is rather different compared to the case of a single SQD, since the presence of the MNP amplifies the external electric field and induces interaction between SQD excitons and localized surface plasmons [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. A great portion of studies in this area is devoted to population transfer between the ground and single exciton states of the SQD, using external fields and with the MNP present [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 12 , 13 , 14 , 16 ]. In many of these works it is reported that the MNP substantially modifies the period of Rabi oscillations between these states [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ], which can even be destroyed for specific SQD-MNP distances [ 4 , 5 , 8 , 9 ].…”

“…In many of these works it is reported that the MNP substantially modifies the period of Rabi oscillations between these states [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ], which can even be destroyed for specific SQD-MNP distances [ 4 , 5 , 8 , 9 ]. High levels of population transfer to the exciton state can be achieved by applying carefully designed short [ 12 , 14 , 16 ] and ultra-short [ 13 , 14 , 16 ] pulses, while in another work the presence of MNP has been used to accomplish electromagnetically induced selective excitonic population transfer [ 10 ]. Additionally, optimal control has been exploited to improve population transfer between the lower energy levels of a -type SQD coupled to a MNP [ 15 ], while a mixed scheme of pulsed and continuous wave fields has been recommended to efficiently prepare a single hole spin state in a SQD-MNP system [ 11 ].…”