A plasmonic nanoantenna based triggered single photon source

Highly integrated single photon sources are key components in future quantum-optical circuits. Whereas the probabilistic generation of single photons can routinely be done by now, their triggered generation is a much greater challenge. Here, we describe the triggered generation of single photons in a hybrid plasmonic device. It consists of a lambda-type quantum emitter coupled to a multimode optical nanoantenna. For moderate interaction strengths between the subsystems, the description of the quantum optical evolution can be simplified by an adiabatic elimination of the electromagnetic fields of the nanoantenna modes. This leads to an insightful analysis of the emitter's dynamics, entails the opportunity to understand the physics of the device, and to identify parameter regimes for a desired operation. Even though the approach presented in this work is general, we consider a simple exemplary design of a plasmonic nanoantenna, made of two silver nanorods, suitable for triggered generation of single photons.Comment: 13 pages, 7 figure

Análisis de los beneficios y barreras a la implantación de los sistemas de gestión de la calidad en empresas andaluzas

Universidad de Sevilla. Grado en Finanzas y Contabilida

Nanoantennas for ultrabright single photon sources

We propose to use nanoantennas coupled to incoherently pumped quantum dots for ultra-bright single photon emission. Besides fully quantum calculations, we analyze an analytical expression for the emitted photon rate. From these analytical considerations it turns out that the Purcell factor and the pumping rate are the main quantities of interest. We also disclose a trade-off between the emitted photon rate and the nonclassical nature of the emitted light. This trade-off has to be considered while designing suitable nanoantennas, which we also discuss in depth

Strong coupling of optical nanoantennas and atomic systems

An optical nanoantenna and adjacent atomic systems are strongly coupled when an excitation is repeatedly exchanged between these subsystems prior to its eventual dissipation into the environment. It remains challenging to reach the strong coupling regime but it is equally rewarding. Once being achieved, promising applications as signal processing at the nanoscale and at the single photon level would immediately come into reach. Here, we study such hybrid configuration from different perspectives. The configuration we consider consists of two identical atomic systems, described in a two-level approximation, which are strongly coupled to an optical nanoantenna. First, we investigate when this hybrid system requires a fully quantum description and provide a simple analytical criterion. Second, a design for a nanoantenna is presented that enables the strong coupling regime. Besides a vivid time evolution, the strong coupling is documented in experimentally accessible quantities, such as the extinction spectra. The latter are shown to be strongly modified if the hybrid system is weakly driven and operates in the quantum regime. We find that the extinction spectra depend sensitively on the number of atomic systems coupled to the nanoantenna.Comment: 14 pages, 7 figure

Tunable Graphene Antennas for Selective Enhancement of THz-Emission

In this paper, we will introduce THz graphene antennas that strongly enhance the emission rate of quantum systems at specific frequencies. The tunability of these antennas can be used to selectively enhance individual spectral features. We will show as an example that any weak transition in the spectrum of coronene can become the dominant contribution. This selective and tunable enhancement establishes a new class of graphene-based THz devices, which will find applications in sensors, novel light sources, spectroscopy, and quantum communication devices

Unfair competition governs the interaction of pCPI-17 with myosin phosphatase (PP1-MYPT1).

The small phosphoprotein pCPI-17 inhibits myosin light-chain phosphatase (MLCP). Current models postulate that during muscle relaxation, phosphatases other than MLCP dephosphorylate and inactivate pCPI-17 to restore MLCP activity. We show here that such hypotheses are insufficient to account for the observed rapidity of pCPI-17 inactivation in mammalian smooth muscles. Instead, MLCP itself is the critical enzyme for pCPI-17 dephosphorylation. We call the mutual sequestration mechanism through which pCPI-17 and MLCP interact inhibition by unfair competition: MLCP protects pCPI-17 from other phosphatases, while pCPI-17 blocks other substrates from MLCP\u27s active site. MLCP dephosphorylates pCPI-17 at a slow rate that is, nonetheless, both sufficient and necessary to explain the speed of pCPI-17 dephosphorylation and the consequent MLCP activation during muscle relaxation

Impacts of Accumulated Particulate Organic Matter on Oxygen Consumption and Organic Micro-Pollutant Elimination in Bank Filtration and Soil Aquifer Treatment

Bank filtration (BF) and soil aquifer treatment (SAT) are efficient natural technologies in potable water reuse systems. The removal of many organic micro-pollutants (OMPs) depends on redox-conditions in the subsoil, especially on the availability of molecular oxygen. Due to microbial transformation of particulate and dissolved organic constituents, oxygen can be consumed within short flow distances and induce anoxic and anaerobic conditions. The effect of accumulated particulate organic carbon (POC) on the fate of OMPs in BF and SAT systems is not fully understood. Long-term column experiments with natural sediment cores from the bank of Lake Tegel and from a SAT basin were conducted to investigate the impact of accumulated POC on dissolved organic carbon (DOC) release, on oxygen consumption, on mobilization of iron and manganese, and on the elimination of the organic indicator OMPs. The cores were fed with aerated tap water spiked with OMPs to exclude external POC inputs. Complete oxygen consumption within the first infiltration decimeter in lake sediments caused mobilization of iron, manganese, and DOC. Redox-sensitive OMPs like diclofenac, sulfamethoxazole, formylaminoantipyrine, and gabapentin were eliminated by more than 50% in all sediment cores, but slightly higher residual concentrations were measured in effluents from lake sediments, indicating a negative impact of a high oxygen consumption on OMP removal