Concept

Fluctuations thermodynamiques

Publications associées (31)

Ultraviolet Superradiance from Mega-Networks of Tryptophan in Biological Architectures

Majed Chergui, Katrin Elisabeth Oberhofer

Networks of tryptophan (Trp)& horbar;an aromatic amino acid with strong fluorescence response & horbar;are ubiquitous in biological systems, forming diverse architectures in transmembrane proteins, cytoskeletal filaments, subneuronal elements, photorecepto ...

Amer Chemical Soc2024

Light Emission and Conductance Fluctuations in Electrically Driven and Plasmonically Enhanced Molecular Junctions

Christophe Marcel Georges Galland, Konstantin Malchow, Wen Chen, Sakthi Priya Amirtharaj

Electrically connected and plasmonically enhanced molecular junctions combine the optical functionalities of high field confinement and enhancement (cavity function), and of high radiative efficiency (antenna function) with the electrical functionalities o ...

Amer Chemical Soc2024

Impact of microwave beam scattering by density fluctuations on the electron-cyclotron power deposition profile in tokamaks

Stefano Coda, Joan Decker, Oleg Krutkin, Umesh Kumar, Jean Arthur Cazabonne

Electron-cyclotron waves are a tool commonly used in tokamaks, in particular to drive current. Their ability to drive current in a very localized manner renders them an optimal tool for MHD mode mitigation. However, such applications require high accuracy ...

IOP Publishing Ltd2024

Solids that are also liquids: elastic tensors of superionic materials

Nicola Marzari, Tommaso Chiarotti, Giuliana Materzanini

Superionics are fascinating materials displaying both solid- and liquid-like characteristics: as solids, they respond elastically to shear stress; as liquids, they display fast-ion diffusion at normal conditions. In addition to such scientific interest, su ...

NATURE PORTFOLIO2023

Wigner Gaussian dynamics: Simulating the anharmonic and quantum ionic motion

Lorenzo Monacelli

The atomic motion controls important properties of materials, such as thermal transport, phase transitions, and vibrational spectra. However, simulating the ionic dynamics is exceptionally challenging when quantum fluctuations are relevant (e.g., at low te ...

AMER PHYSICAL SOC2023

Machine-learning the electronic density of states: electronic properties without quantum mechanics

Chiheb Ben Mahmoud

The electronic density of states (DOS) quantifies the distribution of the energy levels that can be occupied by electrons in a quasiparticle picture and is central to modern electronic structure theory. It also underpins the computation and interpretation ...

EPFL2023

Adiabatic two-phase pressure drop of carbon dioxide in different channel orientations

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

Adiabatic pressure drop measurements of two-phase Carbon Dioxide (CO2) have been carried out in horizontal, vertical upward and downward direction with a dedicated test facility at the European Organization for Nuclear Research (CERN). A database of more t ...

2022

Unified theory of atom-centered representations and message-passing machine-learning schemes

Michele Ceriotti, Guillaume André Jean Fraux, Sergey Pozdnyakov, Jigyasa Nigam

Data-driven schemes that associate molecular and crystal structures with their microscopic properties share the need for a concise, effective description of the arrangement of their atomic constituents. Many types of models rely on descriptions of atom-cen ...

AIP Publishing2022

Hole-induced anomaly in the thermodynamic behavior of a one-dimensional Bose gas

Riccardo Rota

We reveal an intriguing anomaly in the temperature dependence of the specific heat of a one-dimensional Bose gas. The observed peak holds for arbitrary interaction and remembers a superfluid-to-normal phase transition in higher dimensions, but phase transi ...

SCIPOST FOUNDATION2022

Local Kernel Regression and Neural Network Approaches to the Conformational Landscapes of Oligopeptides

Michele Ceriotti, Anne-Clémence Corminboeuf, Alberto Fabrizio, Benjamin André René Meyer, Edgar Albert Engel, Raimon Fabregat I De Aguilar-Amat, Veronika Juraskova

The application of machine learning to theoretical chemistry has made it possible to combine the accuracy of quantum chemical energetics with the thorough sampling of finite-temperature fluctuations. To reach this goal, a diverse set of methods has been pr ...

2022

Thermal critical points from competing singlet formations in fully frustrated bilayer antiferromagnets

Frédéric Mila, Antoine Yves Dimitri Fache

We examine the ground-state phase diagram and thermal phase transitions in a plaquettized fully frustrated bilayer spin-1/2 Heisenberg model. Based on a combined analysis from sign-problem free quantum Monte Carlo simulations, perturbation theory, and free ...

AMER PHYSICAL SOC2022

A numerical study of the statistics of roughness parameters for fluctuating interfaces

Elisabeth Agoritsas

Self-affine rough interfaces are ubiquitous in experimental systems, and display characteristic scaling properties as a signature of the nature of disorder in their supporting medium, i.e. of the statistical features of its heterogeneities. Different metho ...

2021

Local excitations in amorphous solids

Wencheng Ji

Amorphous solids are structurally disordered. They are very common and include glasses, colloids, and granular materials, but are far less understood than crystalline solids. Key aspects of these materials are controlled by the presence of excitations in w ...

EPFL2021

Finite-temperature materials modeling from the quantum nuclei to the hot electron regime

Michele Ceriotti, Chiheb Ben Mahmoud, Nataliya Lopanitsyna

Atomistic simulations provide insights into structure-property relations on an atomic size and length scale, that are complementary to the macroscopic observables that can be obtained from experiments. Quantitative predictions, however, are usually hindere ...

2021

Fluctuation-dissipation relations in the absence of detailed balance: formalism and applications to active matter

Ignacio Pagonabarraga Mora, Sara Dal Cengio

We present a comprehensive study about the relationship between the way detailed balance is broken in non-equilibrium systems and the resulting violations of the fluctuation-dissipation theorem. Starting from stochastic dynamics with both odd and even vari ...

IOP PUBLISHING LTD2021

Thermally activated flow in models of amorphous solids

Matthieu Wyart, Thomas Willem Jan de Geus, Wencheng Ji, Marko Popovic

Amorphous solids yield at a critical value Sigma(c) of the imposed stress Sigma through a dynamical phase transition. While sharp in athermal systems, the presence of thermal fluctuations leads to the rounding of the transition and thermally activated flow ...

AMER PHYSICAL SOC2021

Global Free-Energy Landscapes as a Smoothly Joined Collection of Local Maps

Michele Ceriotti, Gareth Aneurin Tribello, Federico Giberti

Enhanced sampling techniques have become an essential tool in computational chemistry and physics, where they are applied to sample activated processes that occur on a time scale that is inaccessible to conventional simulations. Despite their popularity, i ...

2021

A general and efficient framework for atomistic machine learning

Félix Benedito Clément Musil

Over the last two decades, many technological and scientific discoveries, ranging from the development of materials for energy conversion and storage through the design of new drugs, have been accelerated by the use of preliminary in silico experiments, to ...

EPFL2021

Atomic scale investigations of fracture in metal alloys

Eleanor Yi Kei Mak

The demand for metal alloys with superior structural performance in industrial applications continues to increase, as does the need for more-energy efficient materials and methods. Many materials that are otherwise attractive for structural applications ar ...

EPFL2021

Photo- and thermally-induced electronic and structural dynamics in perovskites and transition metal oxides

Oliviero Cannelli

In this thesis, we exploited optical and X-ray pump-probe methods in a synergistic approach to study the interplay of the electronic, spin and structural degrees of freedom in two class of complex systems relevant for solar energy conversion applications: ...

EPFL2021