Resonance fluorescence spectrum of ap-doped quantum dot coupled to a metallic nanoparticle

Abstract

The resonance fluorescence spectrum (RFS) of a hybrid system consisting of a p-doped semiconductor quantum dot (QD) coupled to a metallic nanoparticle (MNP) is analyzed. The quantum dot is described as a four-level atom-like system using the density matrix formalism. The lower levels are Zeeman-split hole spin states and the upper levels correspond to positively charged excitons containing a spin-up, spin-down hole pair and a spin electron. A linearly polarized laser field drives two of the optical transitions of the QD and produces localized surface plasmons in the nanoparticle which act back upon the QD. The frequencies of these localized plasmons are very different along the two principal axes of the nanoparticle, thus producing an anisotropic modification of the spontaneous emission rates of the allowed optical transitions which is accompanied by very minor local field corrections. This manifests into dramatic modifications in the RFS of the hybrid system in contrast to the one obtained for the isolated QD. The RFS is analyzed as a function of the nanoparticle's aspect ratio, the external magnetic field applied in the Voigt geometry, and the Rabi frequency of the driving field. It is shown that the spin of the QD is imprinted onto certain sidebands of the RFS, and that the signal at these sidebands can be optimized by engineering the shape of the MNP.

Resonance fluorescence spectrum of aΛ-type quantum emitter close to a metallic nanoparticle

“…This work is related to previous works carried out by us [17] and other authors [14-16, 18, 19] on the spectral properties of the spontaneous photons produced in externally driven quantum systems coupled to a metallic nanostructure. These studies revealed the possibility of changing the linewidth and location of the different sidebands of the spectra of the spontaneous photons arising from the back-action of the electric field generated by the metallic nanostructure on the quantum system (exciton-plasmon coupling).…”

“…The ultracompact optical mode volume achieved in plasmon nanostructures leads to a large resonant enhancement of the local field near the MNP [1][2][3][4], as well as the modification of spontaneous emission rates of the emitter's optical transitions [5][6][7][8][9][10][11]. The exciton-plasmon coupling has received a great deal of attention leading to interesting phenomena like changes in photoluminescence lifetimes [12], in photon statistics [13], in the resonance fluorescence [14][15][16][17][18][19], in plasmon-induced quantum interference effects [20][21][22], in the control over population dynamics [23][24][25][26], and over nonlinear optical processes [27][28][29][30][31][32][33][34].…”

Spin initialization of a p-doped quantum dot coupled to a bowtie nanoantenna

“…(14). The above mentioned mechanisms strongly depend on the QD-nanoantenna distance R. These mechanisms have been explored in the context of obtaining hole spin initialization [13] and in the case of considering the modification in the resonance fluorescence spectrum arising from the plasmonic interaction [38].…”

“…The calculation of S inc (ω) requires the calculation of the two-time correlation function, which can be performed by means of the quantum-regression theorem [55,54] (see Ref. [38] for details). The central line exhibits a three peak structure.…”

“…We show that a proper adjustment of the shape and separation of the nanoantenna (the gap distance), and the Rabi frequency of the driving field allows for a faster spin initialization than for the isolated QD. In addition, we present a new method to estimate whether the spin has been effectively initialized, the so-called characteristic time (T 0 ), which differs from previous methods used to estimate such instants of time [11,38]. The current proposal to estimate T 0 is more robust than that previously used, and allows for the specification of an interval of Rabi frequencies which should produce the spin initialization of the QD.…”