Publications associées à Modèle en couches

Electromagnetic processes of nuclear excitation: from direct photoabsorption to free electron and muon capture

In the vast expanse of the Universe and on our planet, nuclei exist in a state of excitement. These excited nuclear states (isomers) can persist for varying periods, from fractions of a second to billions of years and beyond, before decaying to their groun ...

EPFL2023

Magnetic Properties of Surface Adsorbed Metal Adatoms and Dimers

Dante Philippe Sblendorio

This thesis investigates the magnetic properties of single atoms and dimers adsorbed on graphene and oxide decoupling layers supported by single crystal metal substrates, using scanning tunneling microscopy (STM) and spin-polarized scanning tunneling micro ...

EPFL2022

Dynamical Control of Nuclear Isomer Depletion via Electron Vortex Beams

Fabrizio Carbone, Simone Gargiulo

Some nuclear isomers are known to store a large amount of energy over long periods of time, with a very high energy-to-mass ratio. Here, we describe a protocol to achieve the external control of the isomeric nuclear decay by using electron vortex beams who ...

AMER PHYSICAL SOC2022

Measuring the Intra-Atomic Exchange Energy in Rare-Earth Adatoms

Harald Brune, François Patthey, Stefano Rusponi, Marina Pivetta

We present the first experimental determination of the intra-atomic exchange energy between the inner 4f and the outer 6s5d shells in rare-earth elements. Inelastic electron tunneling spectroscopy on individual rare-earth atoms adsorbed on metal-supported ...

American Physical Society2020

Low-energy excitations in type-II Weyl semimetal T-d-MoTe2 evidenced through optical conductivity

Ana Akrap

Molybdenum ditelluride, MoTe2, is a versatile material where the topological phase can be readily tuned by manipulating the associated structural phase transition. The fine details of the band structure of MoTe2, key to understanding its topological proper ...

AMER PHYSICAL SOC2020

NMR Study of Spin Dynamics in V7Zn and V7Ni Molecular Rings

Alice Radaelli

We present a(1)H NMR investigation of spin dynamics in two finite integer spin molecular nanomagnetic rings, namely V7Zn and V7Ni. This study could be put in correlation with the problem of Haldane gap in infinite integer spin chains. While V7Zn is an appr ...

2020

A Weak Form Implementation of Nonlinear Axisymmetric Shell Equations With Examples

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla

We present a weak form implementation of the nonlinear axisymmetric shell equations. This implementation is suitable to study the nonlinear deformations of axisymmetric shells, with the capability of considering a general mid-surface shape, non-homogeneous ...

2019

To bend or not to bend, the dilemma of multiple bonds

Michele Pizzochero

Beyond the second row of the periodic table, the nature of the multiple bonds between the elements of the main groups remains yet elusive, and "non-classical" bonding schemes are often invoked for their description. Here, focusing on group 14, we have perf ...

ROYAL SOC CHEMISTRY2019

Communication: Constrained molecular dynamics for polarizable models

Sara Bonella, Alessandro Coretti

A new algorithm to solve numerically the evolution of empirical shell models of polarizable systems is presented. It employs constrained molecular dynamics to satisfy exactly, at each time step, the crucial condition that the gradient of the potential with ...

2018

Experimental campaign on thin RC columns prone to out-of-plane instability: numerical simulation using shell element models

Katrin Beyer, João Saraiva Esteves Pacheco de Almeida, Angelica Rosso, Lisandro Arturo Jimenez Roa

Construction of multi-storey reinforced concrete (RC) wall buildings in areas of moderate to high seismicity has become a common practice in several Latin-American countries such as Colombia, Peru, Ecuador and Mexico. The large material cost has led to the ...

2017

Adsorption Sites of Metal Atoms on MgO Thin Films and Rotational Quantum State Spectroscopy of Physisorbed H₂

Edgar Fernandes

The work presented in this thesis covers two different topics of surface science, both investigated with the scanning tunneling miscroscopy and spectroscopy at low temperatures (5~K). First, we are interested in the spectroscopic properties of physisorbed ...

EPFL2017

Method for the generation of radicals for dynamic nuclear polarization and uses thereof for nmr, mrs and mri

Christophe Roussel, Arnaud Comment, Tim Rolf Eichhorn

A method for the preparation of a sample comprising highly polarized nuclear spins is proposed, comprising at least the following steps: a) provision of molecules with 1,2-dione structural units and/or molecules with 2,5-diene-1,4-dione structural units in ...

2016

Direct measurement of the bulk spin structure of noncentrosymmetric BiTeCl

Jan Hugo Dil, Stefan Peter Muff

A strong spin-orbit interaction leads to a Rashba-type splitting of the bulk bands of BiTeCl, which results in toroidal Fermi surfaces with distinct spin structures depending on the chemical potential. Here, we present spin-and angle-resolved photoelectron ...

American Physical Society2015

Extracting partial decay rates of helium from complex rotation: autoionizing resonances of the one-dimensional configurations

Pierre Lugan

Partial autoionization rates of doubly excited one-dimensional helium in the collinear Zee and eZe configuration are obtained by means of the complex rotation method. The approach presented here relies on a projection of back-rotated resonance wave functio ...

IOP Publishing2015

Challenges in preparing, preserving and detecting para-water in bulk: overcoming proton exchange and other hurdles

Geoffrey Bodenhausen, Aurélien Bornet, Sami Jannin, Jonas Milani, Diego Carnevale, Nicola Salvi, Daniele Mammoli, Roberto Buratto, Estel Canet Martinez

Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes ...

Royal Society of Chemistry2015

Exploring Ligand Affinities for Proteins by NMR of Long-Lived States

Roberto Buratto

The detection of molecules that can bind to active sites of protein targets and the measurement of their affinities is a promising application of NMR. Nowadays, the screening of drug candidates is routinely done by NMR in pharmaceutical industry. We have p ...

EPFL2015

Exploring the spin-orbital ground state of Ba3CuSb2O9

Frédéric Mila, Andrew James Smerald

Motivated by the absence of both spin freezing and a cooperative Jahn-Teller effect at the lowest measured temperatures, we study the ground state of Ba3CuSb2O9. We solve a general spin-orbital model on both the honeycomb and the decorated honeycomb lattic ...

2014

Evaluation of the importance of spin-orbit couplings in the nonadiabatic quantum dynamics with quantum fidelity and with its efficient “on-the-fly” ab initio semiclassical approximation

Jiri Vanicek, Tomas Zimmermann

We propose to measure the importance of spin-orbit couplings (SOCs) in the nonadiabatic molecular quantum dynamics rigorously with quantum ﬁdelity. To make the criterion practical, quantum ﬁdelity is estimated efﬁciently with the multiple-surface dephasing ...

American Institute of Physics2012

Theoretical investigations of magnetic properties of MRI contrast agents and carbon nanostructures

Oleg Yazyev

The phenomenon of magnetism is one of the key components of today's technological progress. Magnetic interactions and magnetic materials are essential for the scientific disciplines of physics, chemistry and biology, making this subject truly multidiscipli ...

EPFL2007

Identification of an RVB liquid phase in a quantum dimer model with competing kinetic terms

Frédéric Mila, François Vernay

Starting from the mean-field solution of a spin-orbital model of LiNiO2, we derive an effective quantum dimer model (QDM) that lives on the triangular lattice and contains kinetic terms acting on four-site plaquettes and six-site loops. Using exact diagona ...

2006