Strong coupling through optical positioning of a quantum dot in a photonic crystal cavity

Abstract

Single self-assembled InAs quantum dots embedded in GaAs photonic crystal defect cavities are a promising system for cavity quantum electrodynamics experiments and quantum information schemes. Achieving controllable coupling in these small mode volume devices is challenging due to the random nucleation locations of individual quantum dots. We have developed an all optical scheme for locating the position of single dots with sub-10 nm accuracy. Using this method, we are able to deterministically reach the strong coupling regime with a spatial positioning success rate of approximately 70%. This flexible method should be applicable to other microcavity architectures and emitter systems.

Entanglement creation in a quantum-dot–nanocavity system by Fourier-synthesized acoustic pulses

“…This two-level system is formed by the crystal ground state of the QD and its fundamental optical excitation with one electron-hole pair, a single exciton X [9]. Such systems have been studied over the past decade by several groups [10] who successfully demonstrated in key experiments both, the weak [11][12][13] and the strong [14][15][16][17][18][19] coupling regime of cavity QED. Most importantly, this type of nanocavity uniquely allows for a dynamic and reversible spectral control of the optical mode at Gigahertz frequencies by the coherent acoustic phonon field of a radio frequency SAW [20] which is crucial for the implementation of LZ-gates.…”

Strain tuning of quantum dot optical transitions via laser-induced surface defects

“…A0 r (17) Note that the strain components that affect the conduction band and the heavy-hole valence band do not depend on relative angle θ. This explains the data shown in Fig.…”

“…Techniques have been developed to control the position of quantum dots using a nanohole as a nucleation center and then fabricating a cavity around 15 or to position a nanocavity around a randomly located emitter. 16,17 The optical properties of a given dot are determined by its composition, size and the local strain: therefore it is not possible to have a deterministic control on the frequency of the quantum dot optical transition. This is a crucial problem for cavity quantum electrodynamics, since the frequency of the emitter and the cavity mode resonance must be matched with high precision.…”

Effect of a nanoparticle on the optical properties of a photonic crystal cavity: theory and experiment

“…Studies of the interaction between a single quantum emitter and a PC cavity, such as those described in [5][6][7][8][9][10][11], commonly make use of L3 and S1 cavities ( Fig. 1), as simulations indicate that these can have high quality factors.…”

“…While single, selfassembled quantum dots can be naturally embedded in the PC material during substrate growth, after which a PC cavity can be fabricated around a specific dot using precise lithographic techniques [5,6], other types of single quantum emitters generally require a different approach [7,8].…”