Strong Optomechanical Coupling at Room Temperature by Coherent Scattering

Quantum control of a system requires the manipulation of quantum states faster than any decoherence rate. For mesoscopic systems, this has so far only been reached by few cryogenic systems. An important milestone towards quantum control is the so-called strong coupling regime, which in cavity optomechanics corresponds to an optomechanical coupling strength larger than cavity decay rate and mechanical damping. Here, we demonstrate the strong coupling regime at room temperature between a levitated silica particle and a high finesse optical cavity. Normal mode splitting is achieved by employing coherent scattering, instead of directly driving the cavity. The coupling strength achieved here approaches three times the cavity linewidth, crossing deep into the strong coupling regime. Entering the strong coupling regime is an essential step towards quantum control with mesoscopic objects at room temperature

Microdroplet Approach for Measuring Aqueous Solubility and Nucleation Kinetics of a Metastable Polymorph: The case of KDP Phase IV

Solubility and interfacial energy are two fundamental parameters underlying the competitive nucleation of polymorphs. However, solubility measurement of metastable phases comes with a risk of solventmediated transformations which can render the results unreliable. In this work, we present a rapid microfluidic technique for measuring aqueous solubility of the metastable form using KDP Phase IV as a model system. This bracketing approach involves analyzing the dissolution behavior of crystals in contact with supersaturated microdroplets generated via evaporation. Then, with the help of our recently developed nucleation time measurement technique, together with Mersmann calculation of interfacial energies from solubilities, we were able to access the interfacial energies of both metastable and stable phases. To gain further insights into the observed nucleation behavior, we employed the Classical Nucleation Theory (CNT) to model the competition of polymorphs using our measured solubility and calculated interfacial energies. The results show that the stable form is favored at lower supersaturation while the metastable form is favored at higher supersaturation, in good agreement with our observations and experimental reports in the literature. Overall, our microfluidic approach allows access to unprecedentedly deep levels of supersaturation and reveals an interesting interplay between thermodynamics and kinetics in polymorphic nucleation. The experimental methods and insights presented herein can be of great interest, notably in the mineral processing and pharmaceutical industry

Structure des couronnes et variation de l’épaisseur et de la surface d’aubier chez l’Angélique deGuyane (Dicorynia guianensis Amsh., Caesalpinioideae, Fabaceae)

International audienceL'Angélique (Dicorynia guianensis Amsh.) représente environ 35% de laproduction de bois d'oeuvre en Guyane. Cependant, la stratégie de duraminisationdite ‘tardive’ chez cette essence entraîne une grande variabilité de l'épaisseurd'aubier (Fig. 1A) et par conséquent, influence la proportion exploitable de lagrume. La relation entre quantité de bois de coeur et diamètre à 1m30 (DBH) (e.g.Carrodus (1972), Wilkes (1991), Pinto et al. (2004), Wang et al. (2010)), ne permetpas une estimation suffisamment précise de la quantité de duramen et/ou d’aubier.A ce jour, très peu d’études mettent en lien la structure de la couronne et/ou lestatut social de l’individu avec la quantité de duramen (e.g. Pazdrowski et al.(2009), Nawrot et al. (2008)). Or, une grande diversité de structures des couronnesest observable au sein d’une même classe de diamètre (Fig. 1B).Ici, nous proposons une méthode visuelle et rapide de diagnostic architectural desarbres permettant d’améliorer l’estimation de la quantité de duramen dans letronc

The EGIM, modular though generic addresses the requirements of the EMSO platforms

The EGIM (EMSO Generic Instrument Module ) is designed to consistently and continuously measure parameters of interest for most major science areas covered by EMSO. This research infrastructure provides accurate records on marine environmental changes from distributed regional nodes around Europe. The system can deliver data that can support the Global Ocean Observing System –Essential Ocean Variables concept, as well as the Marine Strategy Framework Directive towards evaluating environmentalstatus. The EGIM is flexible for adaptation according to site and disciplinespecific requirements. Inter - operability and capacity of future evolution of the system are key aspects of the modularity. The EGIM is able to operate on any EMSO node type: mooring line, sea bed station, cabled or non - cabled and surface buoy to monitor environmental parameters over a wide depth range. Operating modes, power requirements, mechanical design can adapt to the various EMSO node configurations. In addition to sensors already included in the EGIM prototype (temperature, conductivity, pressure, dissolved Oxygen, Turbidity, currents and passive acoustics) the EGIMcan host up to five additional sensors such as chl -a, pCO 2, pH, seismic and photographic/video images ornew sensors. The EGIM provides all the sensor hosting services required ,for instance power distribution, positioning , and protection against bio -fouling . Within EMSO , the EGIM aimsto have a number of ocean locations where the same set of core variables are measured homogeneously: using the same hardware, same sensor references, same qualification methods, same calibration methods, same data format and access and the same maintenance procedures. It’s compact and modular nature allows for flexible deploymentscenarios that include being able to accommodate new instruments such for Essential Ocean Variables and other needs as theirtechnology readiness levels improve.Peer ReviewedPostprint (published version

CNT effective interfacial energy and pre-exponential kinetic factor from measured NaCl crystal nucleation time distributions in contracting microdroplets

Nucleation, the birth of a stable cluster from disorder, is inherently stochastic. Yet up to date, there are no quantitative studies on NaCl nucleation that accounts for its stochastic nature. Here, we report the first stochastic treatment of NaCl-water nucleation kinetics. Using a recently developed microfluidic system and evaporation model, our measured interfacial energies extracted from a modified Poisson distribution of nucleation time show an excellent agreement with theoretical predictions. Furthermore, analysis of nucleation parameters in 0.5 pL, 1.5pL and 5.5 pL microdroplets reveals an interesting interplay between kinetic confinement and shifting of nucleation mechanisms. Overall, our findings highlight the need to treat nucleation stochastically rather deterministically to bridge the gap between theory and experiment