Publications related to Topography and work function measurements of thin MgO(001) films on Ag(001) by nc-AFM and KPFM

Electrokinetic, electrochemical, and electrostatic surface potentials of the pristine water liquid-vapor interface

Although conceptually simple, the air-water interface displays rich behavior and is subject to intense experimental and theoretical investigations. Different definitions of the electrostatic surface potential as well as different calculation methods, each ...

AIP Publishing2022

On the durability of surgical masks after simulated handling and wear

Véronique Michaud, Vincent Marc Varanges, Jian Wang, Baris Çaglar, Yann Albert Gérard Lebaupin, René M. Rossi

After the spread of COVID-19, surgical masks became highly recommended to the public. They tend to be handled and used multiple times, which may impact their performance. To evaluate this risk, surgical masks of Type IIR were submitted to four simulated tr ...

Nature Research2022

Grassmannian diffusion maps based surrogate modeling via geometric harmonics

Ketson Roberto Maximiano Dos Santos

A novel surrogate model based on the Grassmannian diffusion maps (GDMaps) and utilizing geometric harmonics (GH) is developed for predicting the response of complex physical phenomena. The method utilizes GDMaps to obtain a low-dimensional representation o ...

Wiley2022

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

Klaus Kern, Markus Ternes, Abhishek Grewal

Combined scanning tunnelling and atomic force microscopy using a qPlus sensor enables the measurement of electronic and mechanic properties of two-dimensional materials at the nanoscale. In this work, we study hexagonal boron nitride (h-BN), an atomically ...

BEILSTEIN-INSTITUT2021

Mechanical resonators with high dissipation dilution in precision and quantum measurements

Sergey Fedorov

Position measurements of mechanical oscillators underpin experiments spanning from applied nanoscale sensing to endeavors aiming to resolve open fundamental problems of modern physics. Sufficiently precise position measurements are also used for engineerin ...

EPFL2021

Highly spatially resolved mapping of the piezoelectric potentials in InGaN quantum well structures by off-axis electron holography

Victor Carle Adrien Boureau

The internal fields in 2.2nm thick InGaN quantum wells in a GaN LED structure have been investigated by using aberration-corrected off-axis electron holography with a spatial resolution of better than 1nm. To improve the spatial resolution, different types ...

2020

Interplay of anomalous strain relaxation and minimization of polarization changes at nitride semiconductor heterointerfaces

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Yi Wang

We present a methodology to quantify polarization and electron affinity changes at interfaces by combining scanning tunneling spectroscopy, off-axis electron holography in transmission electron microscopy (TEM), and self-consistent calculations of the elec ...

AMER PHYSICAL SOC2020

Negative capacitance semiconductor sensor

Mihai Adrian Ionescu, Ali Saeidi, Francesco Bellando

The present invention relates to a semiconductor sensor (1) comprising: a source element (17, 19); a drain element (21, 23); a semiconductor channel element (25) between the source element (17, 19) and the drain element (21, 23) for forming an electrically ...

2020

Electrosorption at metal surfaces from first principles

Nicola Marzari

Electrosorption of solvated species at metal electrodes is a most fundamental class of processes in interfacial electrochemistry. Here, we use its sensitive dependence on the electric double layer to assess the performance of ab initio thermodynamics appro ...

NATURE PUBLISHING GROUP2020

Self-Assembly at Water Nanodroplet Interfaces Quantified with Nonlinear Light Scattering

Sylvie Roke, Nikolay Smolentsev

The interfaces of water micro- and nanodroplets drive environmental, medical, catalytic, biological, and chemical biphasic processes. The interfacial droplet structure and electrostatics greatly determine the reactivity and efficiency of these processes. D ...

AMER CHEMICAL SOC2020

Electric Field Analysis and Measurement for a Resistively Loaded Monocone

Tingyong Jiang

A novel resistively loaded monocone was proposed to extend the application for electric field calibration. Electric field analysis and measurement were carried out to verify the design of the proposed monocone. As revealed by the results, the S-11 of the m ...

IEEE2020

Quantum Measurement of Mechanical Motion close to the Standard Quantum Limit

Liu Qiu

In quantum mechanics, the Heisenberg uncertainty principle places a fundamental limit in the measurement precision for certain pairs of physical quantities, such as position and momentum, time and energy or amplitude and phase. Due to the Heisenberg uncert ...

EPFL2020

Incorporating long-range physics in atomic-scale machine learning

Michele Ceriotti, Andrea Grisafi

The most successful and popular machine learning models of atomic-scale properties derive their transferability from a locality ansatz. The properties of a large molecule or a bulk material are written as a sum over contributions that depend on the configu ...

2019

Evaluating Charge Equilibration Methods To Generate Electrostatic Fields in Nanoporous Materials

Berend Smit, Daniele Ongari, Peter George Boyd, Amber Kashan Mace, Özge Kadioglu

Charge equilibration (Qeq) methods can estimate the electrostatic potential of molecules and periodic frameworks by assigning point charges to each atom, using only a small fraction of the resources needed to compute density functional (DFT)-derived charge ...

2019

Decisive role of nuclear quantum effects on surface mediated water dissociation at finite temperature

Michele Ceriotti, Mariana Rossi Carvalho

Water molecules adsorbed on inorganic substrates play an important role in several technological applications. In the presence of light atoms in adsorbates, nuclear quantum effects (NQEs) influence the structural stability and the dynamical properties of t ...

2018

Peptide-Cation Systems: Conformational Search, Benchmark Evaluation, and Force Field Parameter Adjustment Using Regularized Linear Regression

Markus Schneider

Metal cations often play an important role in shaping the three-dimensional structure of peptides. As an example, the model system AcPheAla5LysH+ is investigated in order to fully understand the forces that stabilize its helical structure. In particular, t ...

EPFL2018

Excitonic Emission of Monolayer Semiconductors Near-Field Coupled to High-Q Microresonators

Tobias Kippenberg, Nicolas Piro Mastracchio, Clément Christian Javerzac-Galy, Ryan Daniel Schilling, Anshuman Kumar, Sina Khorasani

We present quantum yield measurements of single layer WSe2 (1L-WSe2) integrated with high-Q (Q > 106) optical microdisk cavities, using an efficient (η > 90%) near-field coupling scheme based on a tapered optical fiber. Coupling of the excitonic emission i ...

American Chemical Society (ACS)2018

3D Reconstruction of Optical Diffraction Tomography Based on a Neural Network Model

Morteza Hasani Shoreh

Optical tomography has been widely investigated for biomedical imaging applications. In recent years, it has been combined with digital holography and has been employed to produce high quality images of phase objects such as cells. In this Thesis, we look ...

EPFL2018

Implementation of drift velocities and currents in SOLEDGE2D-EIRENE

Nicolas Mellet, Eric Serre, Davide Galassi

In order to improve cross-field transport description, drifts and currents have been implemented in SOLEDGE2D-EIRENE. The derivation of an equation for the electric potential is recalled. The resolution of current equation is tested in a simple slab case. ...

Elsevier2017

A generalized Poisson and Poisson-Boltzmann solver for electrostatic environments

Nicola Marzari, Oliviero Andreussi

The computational study of chemical reactions in complex, wet environments is critical for applications in many fields. It is often essential to study chemical reactions in the presence of applied electrochemical potentials, taking into account the non-tri ...

Amer Inst Physics2016