Plasmon-assisted two-photon Rabi oscillations in a semiconductor quantum dot – metal nanoparticle heterodimer

Abstract

Tho-photon Rabi oscillations hold potential for quantum computing and quantum information processing, because during a Rabi cycle a pair of entangled photons may be created. We theoretically investigate the onset of this phenomenon in a heterodimer comprising a semiconductor quantum dot strongly coupled to a metal nanoparticle. Two-photon Rabi oscillations in this system occur due to a coherent two-photon process involving the ground-to-biexciton transition in the quantum dot. The presence of a metal nanoparticle nearby the quantum dot results in a self-action of the quantum dot via the metal nanoparticle, because the polatization state of the latter depends on the quantum state of the former. The interparticle interaction gives rise to two principal effects: (i) -enhancement of the external field amplitude and (ii) -renormalization of the quantum dot's resonance frequencies and relaxation rates of the off-diagonal density matrix elements, both depending on the populations of the quantum dot's levels. Here, we focus on the first effect, which results in interesting new features, in particular, in an increased number of Rabi cycles per pulse as compared to an isolated quantum dot and subsequent growth of the number of entangled photon pairs per pulse. We also discuss the destructive role of radiative decay of the excitonic states on two-photon Rabi oscillations for both an isolated quantum dot and a heterodimer.

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

“…Since the applied pulses have been obtained independently of the relaxation mechanisms affecting SQD, an interesting future work would be to investigate their performance when taking these phenomena into account. Another possible test is to evaluate the efficiency of obtained pulses using different relaxation rates for the excited states and different dipole moments for the ground to exciton and exciton to biexciton transitions, as in the model of [ 54 ]. Of course, with the accumulation of all these imperfections, it is probably better to recourse to numerical optimization in order to find the pulses which optimize the biexciton transfer, as we recently did for the fast spin initialization of a quantum dot coupled to a two-dimensional nanostructure [ 63 , 64 , 65 ].…”

“…In Ref. [54] the two-photon Rabi oscillations in this system have been explored, while in our recent work [55] we showed how population transfer to the biecxiton state can be efficiently achieved by applying linearly polarized pulses with hyperbolic secant profile.…”

“…In this article, we also examine the problem of coherently preparing the biexciton state in a coupled SQD-MNP nanosystem, using on-off pulse-sequences that we have previously derived for an isolated SQD [ 43 ]. We use the three-level quantum cascade model for the SQD and the corresponding modified nonlinear density matrix equations, which also take into account the applied electromagnetic field as well as the interaction between MNP surface plasmons and SQD excitons [ 12 , 17 , 18 , 20 , 54 , 56 ]. The externally applied field has linear polarization and is at two-photon resonance with the ground to biexciton transition, while the pulses have a simple on-off-on modulation [ 43 ], where the durations of the on-off segments can be found by solving a transcendental equation.…”

Controlling the Pump-Probe Optical Response in Asymmetric Tunneling-Controlled Double Quantum Dot Molecule—Metal Nanoparticle Hybrids

“…In current studies in photonics, coupled structures formed from semiconductor quantum dots and metal particles at the nanoscale play an important role as they give, in many cases, enhanced optical properties in comparison to individual SQDs and MNPs [1]. The coupling of the excitons to plasmons is responsible for the emergence of interesting optical effects from the SQD-MNP structures, including altered excitonic Rabi oscillations [2][3][4], creation and control of optical bistability and multistability [5][6][7][8][9], population transfer to the exciton [10][11][12][13][14] or biexciton state with high accuracy [15][16][17], controlled slow light [18], creation of gain without inversion [19][20][21], strong enhancement of second harmonic generation [22], and strong modification of four-wave mixing, as well as self-or cross-Kerr nonlinearity [23][24][25][26], control of resonance fluorescence [27][28][29][30], and several others [31][32][33][34][35][36][37][38]. These effects can find applications in the construction of efficient optical devices which can be implemented in the fields of nanophotonics and quantum technology.…”

Efficient Biexciton State Preparation in a Semiconductor Quantum Dot‐Metallic Nanoparticle Hybrid Structure Using Transitionless Quantum Driving

“…[35] Interestingly, the problem of coherent preparation and the controlled dynamics of the biexciton state in the SQD-MNP coupled nanosystem remains largely unexplored. Nughoro et al [36] analyzed the two-photon Rabi oscillations in the quantum dot, which involves the transition from the ground to the biexciton state, when the SQD is located near a spherical MNP. Recently, we theoretically demonstrated that efficient transfer of population to the biexciton state may be obtained using hyperbolic secant pulses.…”