-
Sep 25, 2024 | 
link.aps.org | E. Alfinelli |F. Caporaletti |A. Martinelli |Laboratoire Charles Coulomb
We have probed the atomic dynamics of two sodium silicate glasses in a wide wave vector range by means of x-ray photon correlation spectroscopy. The wide angle setup has been modified to cover a Q range that extends to small angles, close to the range normally covered by the usual small-angle x-ray scattering configuration. During irradiation, the oxide samples undergo a transformation to a new amorphous state with different structural and dynamical properties.
-
Sep 17, 2024 | 
link.aps.org | Federico Ghimenti |Ludovic Berthier |Laboratoire Charles Coulomb
Abstract Exerting a nonequilibrium drive on an otherwise equilibrium Langevin process brings the dynamics out of equilibrium but can also speed up the approach to the Boltzmann steady state. Transverse forces are a minimal framework to achieve dynamical acceleration of the Boltzmann sampling. We consider a simple liquid in three space dimensions subjected to additional transverse pairwise forces, and quantify the extent to which transverse forces accelerate the dynamics.
-
Aug 19, 2024 | 
link.aps.org | Minggang Luo |Laboratoire Charles Coulomb |Youssef Jeyar |Brahim Guizal
We investigate the near-field radiative heat transfer between a normally and/or laterally shifted nanoparticle and a planar fused silica slab coated with a strip graphene grating. For this study, we develop and use a scattering matrix approach derived from Fourier modal method augmented with local basis functions. We find that adding a graphene sheet coating on the slab can already enhance the heat flux by about 85%.
-
Jul 31, 2024 | 
link.aps.org | Youssef Jeyar |Laboratoire Charles Coulomb |Minggang Luo |Brahim Guizal
We study the Casimir-Lifshitz force (CLF) between a gold plate and a graphene-covered dielectric grating. Using a scattering matrix (S-matrix) approach derived from the Fourier modal method (FMM), we find a significant enhancement in the CLF as compared to a mere dielectric slab coated with graphene, over a wide range of temperatures. Additionally, we demonstrate that the CLF depends strongly on the chemical potential of graphene, with maximal effects observed at lower filling fractions.
-
Jul 23, 2024 | 
link.aps.org | Supravat Dey |SRM University-AP |Gladys Massiera |Laboratoire Charles Coulomb
Large groups of active cilia collectively beat in a fluid medium as metachronal waves, essential for some microorganisms motility and for flow generation in mucociliary clearance. Several models can predict the emergence of metachronal waves, but what controls the properties of metachronal waves is still unclear.
-
Jul 22, 2024 | 
pubs.rsc.org | Charlotte Allard |Ecole Polytechnique |Laurent Alvarez |Laboratoire Charles Coulomb
Advanced 1D heterostructures based on nanotube templates and molecules†
Recent advancements in materials science have shed light on the potential of exploring hierarchical assemblies of molecules on surfaces, driven by both fundamental and applicative challenges. This field encompasses diverse areas including molecular storage, drug delivery, catalysis, and nanoscale chemical reactions.
-
Jul 11, 2024 | 
link.aps.org | T. Clua-Provost |Laboratoire Charles Coulomb |Z. Mu
The negatively charged boron vacancy (VB−) center in hexagonal boron nitride (hBN) is currently garnering considerable attention for the design of two-dimensional (2D) quantum sensing units. Such developments require a precise understanding of the spin-dependent optical response of VB− centers, which still remains poorly documented despite its key role for sensing applications.
-
Jul 10, 2024 | 
link.aps.org | Alrik Durand |Laboratoire Charles Coulomb |Yoann Baron
Among the wide variety of single fluorescent defects investigated in silicon, numerous studies have focused on color centers with a zero-phonon line around 1.28µm and identified to a common carbon complex in silicon, namely the G center. However, inconsistent estimates regarding their quantum efficiency cast doubt on the correct identification of these individual emitters.
-
Jul 10, 2024 | 
link.aps.org | Federico Ghimenti |Ludovic Berthier |Laboratoire Charles Coulomb
Equilibrium sampling of the configuration space in disordered systems requires algorithms that bypass the glassy slowing down of the physical dynamics. Irreversible Monte Carlo algorithms breaking detailed balance successfully accelerate sampling in some systems. We first implement an irreversible event-chain Monte Carlo algorithm in a model of continuously polydisperse hard disks.
-
Jun 27, 2024 | 
link.aps.org | Matteo Milani |Laboratoire Charles Coulomb |Universite Montpellier |Ty Phou
We present a dynamic light scattering setup to probe, with time and space resolution, the microscopic dynamics of soft matter systems confined within millimeter-sized spherical drops. By using an ad hoc optical layout, we tackle the challenges raised by refraction effects due to the unconventional shape of the samples. We first validate the setup by investigating the dynamics of a suspension of Brownian particles.
