The heaviest element which has been found in nature is uranium with 92 protons. So far, the elements up to atomic number 118 (oganesson) have been discovered and synthesised in the laboratory and the last one was named after the physicist Y. Oganessian in 2016. All transuranium elements are radioactive and their production rates decrease with increasing number of protons. An Island of...
New energy-efficient computer architectures inspired by the mammalian brain have been growing as an alternative to traditional von Neumann computing. Yet, existing hardware implementations use electrons as charge carriers, while neurons rely on transport of ions for both computation and the building of memory. In my presentation, I will show how a two-dimensional electrolyte confined between...
One of the main questions of fundamental physics is the action of gravity on antimatter. We present here the simulation of the last part of the experiment GBAR at CERN, i.e. the measurement of the free fall acceleration 𝑔̅ of antihydrogen atoms in the gravitational field of Earth. It includes the Monte-Carlo generation of trajectories and the analysis leading to the estimation of 𝑔̅. A...
Neutron Stars are compact objects which interior is subject to extreme densities, gravitational fields and magnetic fields. As such conditions cannot yet be reproduced in laboratories, astronuclear physicists use multi-messenger astronomy to turn Neutron Stars into our very own extraterrestrial laboratories for dense matter. We present some recent results established from X-ray measurements of...
More than half of the globe is considered the tropics, thus a proper understanding of the tropical atmosphere is crucial for improved global forecasts as well as the projections of the global climate change. The tropical atmosphere is traditionally considered dominated by moist cumulus convection associated with strongly divergent horizontal flows. The Madden-Julian Oscillation (MJO) is the...
For the commissioning of JT-60SA Tokamak (Japan, beginning of 2021, Project decided in the framework of Broader Approach to ITER Tokamak Project), all the superconducting coils have to be energized with a set of reduced and then nominal current after they became superconducting at 4.5 K cooling temperature with supercritical helium forced flow in Cable-In-Conduit Conductors (CICC).
An...
Electrophysiological recordings during perceptual decision tasks in monkeys suggest that the degree of confidence in a decision is based on a simple neural signal produced by the neural decision process. Attractor neural networks provide an appropriate biophysical modeling framework (Wong and Wang 2006), and account for a variety of experimental results. Here we report on our work providing...
Laser-plasma acceleration is used to accelerate charged particles and can minimize the size of the next-generation accelerators. However, compared to radiofrequency accelerators, the energies of particles are still low. The ion beam produced by the interaction of the target medium and the high-power laser depends mainly on the laser parameters and the target characteristics. To enhance the ion...
In this contribution, we will present new results on optical and structural properties of WS2 (from the TMD semiconductor family) encapsulated monolayer, at the tens of nanometer scale. The strength of this work is the correlation of optical spectra at the nanoscale with structural and chemical maps, connecting what is usually available in optical diffraction limited techniques, such as...
Stars are formed when a humongous molecular clouds collapses under its own gravity giving rise to multiple local collapses within the cloud itself. Stars are never formed in isolation and are always formed in groups. When one cloud collapses it gives rise to formation of multiple stars in the same system. When formed this way the stars share similar chemical properties and are of same ages...
Axions originally emerged as low-energy remnants of the Peccei Quinn solution to the strong CP problem, but they also unavoidably contribute to the energy density of the Universe. The thermal axion population contributes to the effective number of extra relativistic degrees of freedom, whose value is constrained by cosmic microwave background (CMB) experiments.
In the talk I will discuss...
Inflation is a hypothetical very early period of the universe when it was expanding exponentially. It has been introduced to explain the homogeneity and the flatness of the observed universe. Remarkably, inflation provides a very nice explanation for the origin of the tiny fluctuations that we observe in the cosmic microwave background: all the known particles come from one single scalar field...
Resistance to fracture is an essential property for manufacturers, in particular those who work with elastomers. In a highly deformed crosslinked polymer, the force to which each chain is subjected depends on the local structure of the network (length of the chains, number of entanglements, local geometry, etc.). In general, a chain breaking is caused by extreme tension. Following a chain...
Nuclear systems display a huge diversity of properties, proving the complexity of their structure. This complexity has multiple causes, the first one being the inner structure of protons and neutrons. Since they are constituted of quarks, the underlying theory of Quantum ChromoDynamics (QCD) plays an important role in the description of nuclei. However, at the energies involved in nuclear...
Measurements of top quark spin observables in tt ̄ events represents a unique possibility to test the standard model (SM) predictions and probe the new physics effects. Potential deviations from the SM expectations are parametrized within the framework of the Effective Field Theory (EFT). In this presentation, we introduce how to measure the spin correlation between top quarks and we cover...
When a cataclysmic event takes place in the Universe, like the coalescence of compact objects like neutron stars or black holes, it is unveiled through a variety of waves and rays emanating from it. These are considered as messengers that can be detected on Earth through different observatories. Each one of these emissions is a signature of a particular physical phenomenon that is taking...
Brownian motion is certainly one of the most popular stochastic process to model particles in interaction with their surrounding environment. In its simplest form, Brownian motion is driven by an uncorrelated white noise induced by thermal fluctuations. Thanks to its universality, it has proven to be a successful model to describe a wide range of first-passage phenomena whereby a particular...
The James Webb Space Telescope will enable the direct exploration of primeval galaxies near the Epoch of Reionization, at the end of the Dark Ages. To best interpret these upcoming observations in terms of constraints on theories of galaxy formation and evolution, we require models of the light emitted by the first galaxies. A particularly critical task is to identify spectral diagnostics of...
Mott insulators are materials which should have metallic properties according to tight-binding calculations, but are found to have insulating properties instead. This discrepancy between theory and experiments can be explained with the failure of the independent-electron approximation to account for Coulomb interactions, which are not negligible in such materials. When this contribution is...
Second harmonic generation (SHG) is a nonlinear optical process that has been the basis of applications including frequency-doubling of laser sources, characterization of materials and it has also been a subject of fundamental research interest since decades.
Within this context, nonlinear plasmonics is one sub-domain of nanophysics wherein nonlinear optical processes such as SHG are...
