Four wave mixing in 3C SiC Ring Resonators

We demonstrate frequency conversion by four wave mixing at telecommunication wavelengths using an integrated platform in 3C SiC. The process was enhanced by high-Q and small modal volume ring resonators, allowing the use of mW-level CW powers to pump the nonlinear optical process. We retrieved the nonlinear refractive index $n_{2}=(5.31\pm 0.04)\times 10^{-19} m^{2}/W$ of 3C SiC and observed a signal attributed to Raman gain in the structure.Comment: 4 pages, 3 figure

Heralding two- and four-photon path entanglement on chip

Generating quantum entanglement is not only an important scientific endeavor, but will be essential to realizing quantum-enhanced technologies, in particular, quantum-enhanced measurements with precision beyond classical limits. We investigate the heralded generation of multiphoton entanglement for quantum metrology using a reconfigurable integrated waveguide device in which projective measurement of auxiliary photons heralds the generation of path-entangled states. We use four and six-photon inputs, to analyze the heralding process of two- and four-photon NOON states-a superposition of N photons in two paths, capable of enabling phase supersensitive measurements at the Heisenberg limit. Realistic devices will include imperfections; as part of the heralded state preparation, we demonstrate phase superresolution within our chip with a state that is more robust to photon loss

Therapeutic potential of spirituality and mystical experiences in the treatment of substance use disorders.

Objetivo. Este artículo tiene como objetivo ofrecer una descripción general del papel de la espiritualidad, de la fe y de las experiencias místicas en el tratamiento de los trastornos por uso de sustancias (TUS) presentando el caso de la comunidad terapéutica Takiwasi, donde se utilizan plantas psicoactivas, y considerando otras terapias pertenecientes a las medicinas complementarias y alternativas (MCA) que derivan de o tienen conexión con prácticas religiosas o espirituales. Metodología. La investigación se ha basado en la revisión de la literatura científica y gris y en una entrevista realizada con el presidente y fundador del Centro Takiwasi. Resultados y discusión. El sinergismo entre la espiritualidad cristiana y amazónica parece relevante dentro del protocolo Takiwasi. La literatura pone en evidencia el uso de MCA, incluyendo Mindfulness, Respiración Holotrópica y Yoga. Conclusión. La experiencia clínica muestra que la espiritualidad es un factor clave que se debe tener en cuenta en el tratamiento de la adicción y varias prácticas de MCA con connotaciones espirituales muestran un potencial prometedor para el tratamiento de los TUS.Objective. This article aims to give an overview on the role of spirituality, faith and mystical experiences in the treatment of Substance Use Disorders (SUDs) by presenting the case of the therapeutic community Takiwasi, where psychoactive plants are used, and by considering other Complementary and Alternative Medicine (CAM) therapies that are derived from or have connection with religious or spiritual practices. Methodology. The research has been based on the review of scientific and grey literature and on an interview performed with the president and founder of Takiwasi. Results and discussion. Synergism between Christian and Amazonian spirituality appears relevant within the Takiwasi protocol. The use of CAM including Mindfulness, Holotropic Breathwork and Yoga emerge from the literature. Conclusions. Clinical experience show that spirituality is a key factor to be taken into account when considering addiction treatment and several CAM practices with spiritual connotations show promising potential for the treatment of SUDs

Continuous variable entanglement on a chip

Encoding quantum information in continuous variables (CV)---as the quadrature of electromagnetic fields---is a powerful approach to quantum information science and technology. CV entanglement---light beams in Einstein-Podolsky-Rosen (EPR) states---is a key resource for quantum information protocols; and enables hybridisation between CV and single photon discrete variable (DV) qubit systems. However, CV systems are currently limited by their implementation in free-space optical networks: increased complexity, low loss, high-precision alignment and stability, as well as hybridisation, demand an alternative approach. Here we show an integrated photonic implementation of the key capabilities for CV quantum technologies---generation and characterisation of EPR beams in a photonic chip. Combined with integrated squeezing and non-Gaussian operation, these results open the way to universal quantum information processing with light

Coherent coupling between localised and propagating phonon polaritons

Following the recent observation of localised phonon polaritons in user-defined silicon carbide nano-resonators, here we demonstrate coherent coupling between those localised modes and propagating phonon polaritons bound to the surface of the nano-resonator's substrate. In order to obtain phase-matching, the nano-resonators have been fabricated to serve the double function of hosting the localised modes, while also acting as grating for the propagating ones. The coherent coupling between long lived, optically accessible localised modes, and low-loss propagative ones, opens the way to the design and realisation of phonon-polariton based quantum circuits

Integrated quantum photonics

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Cavity-enhanced measurements of defect spins in silicon carbide

The identification of new solid-state defect-qubit candidates in widely used semiconductors has the potential to enable the use of nanofabricated devices for enhanced qubit measurement and control operations. In particular, the recent discovery of optically active spin states in silicon carbide thin films offers a scalable route for incorporating defect qubits into on-chip photonic devices. Here, we demonstrate the use of 3C silicon carbide photonic crystal cavities for enhanced excitation of color-center defect spin ensembles in order to increase measured photoluminescence signal count rates, optically detected magnetic-resonance signal intensities, and optical spin initialization rates. We observe an up to a factor of 30 increase in the photoluminescence and optically detected magnetic-resonance signals from Ky5 color centers excited by cavity-resonant excitation and increase the rate of ground-state spin initialization by approximately a factor of 2. Furthermore, we show that the 705-fold reduction in excitation mode volume and enhanced excitation and collection efficiencies provided by the structures can be used to overcome inhomogenous broadening in order to facilitate the study of defect-qubit subensemble properties. These results highlight some of the benefits that nanofabricated devices offer for engineering the local photonic environment of color-center defect qubits to enable applications in quantum information and sensin