Optical coupling of two distant InAs/GaAs quantum dots by a photonic-crystal microcavity (original) (raw)
Related papers
Strong coupling through optical positioning of a quantum dot in a photonic crystal cavity
Applied Physics Letters, 2009
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.
13th International Conference on Transparent Optical Networks (ICTON), 2011, 2011
In this work we show two different procedures of fabrication aiming towards the systematic positioning of single InAs quantum dots (QDs) coupled to a GaAs photonic crystal (PC) microcavity. The two approaches are based on the molecular beam epitaxial (MBE) growth of site-controlled QDs (SCQDs) on pre-patterned structures. The PC microcavity (PCM) is introduced previous or after the growth, on each case. We demonstrate the InAs SCQD nucleation on pre-patterned PCMs and a method to perform the QD nucleation respect to an etched ruler that is used to position the PC structure after growth. For both types of structures, we have carried out microphotoluminescence (µPL) spectroscopy experiments at 80 K and 4 K.
Photonics: Design, Technology, and Packaging II, 2005
We investigate the use of nanocrystal quantum dots as a versatile quantum bus element for preparing various quantum resources for use in photonic quantum technologies. The ability to Stark tune nanocrystal quantum dots allows an important degree of control over the cavity QED interaction. Using this property along with the bi-exciton transition, we demonstrate a photonic CNOT interaction between two logical photonic qubits comprising two cavity field modes each. We find the CNOT interaction to be a robust generator of photonic Bell states, even with relatively large bi-exciton losses.These results are discussed in light of the current state-ofthe-art of both microcavity fabrication and recent advances in nanocrystal quantum dot technology. Overall, we find that such a scheme should be feasible in the near future with appropriate refinements to both nanocrystal fabrication technology and micro-cavity design. Such a gate could serve as an active element in photonic-based quantum technologies.
Microcavity controlled coupling of excitonic qubits
Nature Communications, 2013
Controlled non-local energy and coherence transfer enables light harvesting in photosynthesis and non-local logical operations in quantum computing. The most relevant mechanism of coherent coupling of distant qubits is coupling via the electromagnetic field. Here, we demonstrate the controlled coherent coupling of spatially separated excitonic qubits via the photon mode of a solid state microresonator. This is revealed by two-dimensional spectroscopy of the sample's coherent response, a sensitive and selective probe of the coherent coupling. The experimental results are quantitatively described by a rigorous theory of the cavity mediated coupling within a cluster of quantum dots excitons. Having demonstrated this mechanism, it can be used in extended coupling channels -sculptured, for instance, in photonic crystal cavities -to enable a long-range, non-local wiring up of individual emitters in solids. arXiv:1206.0592v1 [quant-ph]
2011
Self-assembled semiconductor quantum dots show great potential as efficient semiconductor-based non-classical light sources. However, due to the very nature of the self-assembled growth process, the characteristics of individual dots can vary widely and their spatial location is generally uncontrolled. Using a directed self-assembly process, the nucleation site of single quantum dots are designed through lithography. The site-control is used to facilitate the spatial alignment of single quantum dots to high finesse optical microcavities. The single dot-cavity device is a unique system to study the dot-cavity coupling where the presence of background emitters can be unambiguously ruled out.
Physica E: Low-dimensional Systems and Nanostructures, 2008
Microphotoluminescence measurements on InAs/GaAs quantum rings embedded in a bi-dimensional photonic crystal cavity display enhanced emission intensity of single rings depending on the coupling strength to the cavity modes. The cavity is formed by three holes missing at the center of the photonic crystal structure (a linear 3 defect, L3). Light emission by the quantum rings show sharp lines at low excitation power. They undergo different enhancement factors by the separate effects of the photonic crystal and by coupling to the resonant modes, which show full linear polarization. Upon changing temperature, the uncoupled emission of single quantum rings and the resonant modes undergo different frequency shifts. This allows for an external control of the coupling. r
Journal of Modern Optics, 2021
We theoretically investigate optical bistability, mechanically induced absorption (MIA) and Fano resonance of a hybrid system comprising of a single quantum dot (QD) embedded in a solid state microcavity interacting with the quantized cavity mode and the deformation potential associated with the lattice vibration. We find that the bistability can be tuned by the QD-cavity mode coupling. We further show that the normalized power transmission displays anomalous dispersion indicating that the system can be used to generate slow light. We also demonstrate the possibility of using the system as all optomechanical Kerr switch.
Enhanced coupling of electronic and photonic states in a microcavity-quantum dot system
Spherical microcavities consisting of a dielectric material show unique optical characteristics as resonators in combination with semiconductor nanoparticles. A high quality factor results in a very narrow bandwidth of the resonant modes (whispering-gallery modes) inside the microcavity. The polystyrene microspheres are coated with one monolayer of CdTe nanocrystals which offer a high photostability and a high quantum yield at room temperature. Due to strong confinement of the electrons in all three dimensions, excitation from the quantum dots is highly size-dependent and tuneable over almost the whole visible spectrum. The deposition of the nanocrystals on the sphere surface allows efficient coupling of the light of the CdTe quantum dots into the microcavity. Photoluminescence and Raman spectra were taken with a Renishaw Raman system. The setup is equipped with an Ar + -laser and a HeNe-laser to excite the nanocrystals. Raman measurements show a series of very sharp resonant peaks instead of a continuous spectrum. Strong interaction between the electronic states of the nanocrystals and the resonant modes in the microsphere causes a considerable enhancement of the Raman scattering and luminescence from the CdTe quantum dots in Stokes and anti-Stokes region. Furthermore, a linear blue shift of the resonances in the photoluminescence spectrum was observed during continuous excitation for 18 minutes with a HeNe laser.
Strong-coupling of quantum dots in microcavities
2008
We show that strong-coupling (SC) of light and matter as it is realized with quantum dots (QDs) in microcavities differs substantially from the paradigm of atoms in optical cavities. The type of pumping used in semiconductors yields new criteria to achieve SC, with situations where the pump hinders, or on the contrary, favours it. We analyze one of the seminal experimental observation of SC of a QD in a pillar microcavity [Reithmaier et al., Nature (2004)] as an illustration of our main statements.
Strong coupling between two quantum dots and a photonic crystal cavity using magnetic field tuning
Optics Express, 2011
We demonstrate strong coupling between two indium arsenide (InAs) quantum dots (QDs) and a photonic crystal cavity by using a magnetic field as a frequency tuning method. The magnetic field causes a red shift of an exciton spin state in one QD and a blue shift in the opposite exciton spin state of the second QD, enabling them to be simultaneously tuned to the same cavity resonance. This method can match the emission frequency of two QDs separated by detunings as large as 1.35 meV using a magnetic field of up to 7 T. By controlling the detuning between the two QDs we measure the vacuum Rabi splitting (VRS) both when the QDs are individually coupled to the cavity, as well as when they are coupled to the cavity simultaneously. In the latter case the oscillator strength of two QDs shows a collective behavior, resulting in enhancement of the VRS as compared to the individual cases. Experimental results are compared to theoretical calculations based on the solution to the full master equation and found to be in excellent agreement.