Publications associées à Extension of the dielectric tunability range in ferroelectric materials by electric bias field antiparallel to polarization

Polarization-enhanced GaN Schottky barrier diodes: Ultra-thin InGaN for high breakdown voltage and low Ron

Elison de Nazareth Matioli, Alessandro Floriduz, Zheng Hao

In this work, we present a concept that leverages the strong piezoelectric polarization field in InGaN, which counteracts the external electric field at reverse bias. We show that despite the smaller InGaN band-gap and lower critical electric field, its st ...

2024

Hydrogen-induced tunable remanent polarization in a perovskite nickelate

Michele Kotiuga

Materials with field-tunable polarization are of broad interest to condensed matter sciences and solid-state device technologies. Here, using hydrogen (H) donor doping, we modify the room temperature metallic phase of a perovskite nickelate NdNiO3 into an ...

Nature Portfolio2024

Manufacturing-Enabled Tunability of Linear and Nonlinear Epsilon-Near-Zero Properties in Indium Tin Oxide Nanofilms

Qian Li, Xuanyi Liu, Jiaye Wu

Epsilon-near-zero (ENZ) materialshave attracted great interestdue to their exotic linear and nonlinear responses, which makes itsignificant to tune ENZ wavelengths for wavelength-dependent applications.However, studies to achieve tunability in a wide spect ...

AMER CHEMICAL SOC2023

Time-resolved multi-gate ion sensitive field effect transducer and system and method of operating the same

Jean-Michel Sallese, Adil Koukab

A time-resolved multi-gate ion sensitive field effect transducer, including a silicon layer, a P-doped region in the silicon layer and a first electrode in electric connection with the P doped region, a N-doped region in the silicon layer and a second elec ...

2023

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Optimal enzyme utilization suggests that concentrations and thermodynamics determine binding mechanisms and enzyme saturations

Vassily Hatzimanikatis, Daniel Robert Weilandt, Asli Sahin

One of the main challenges hampering the development of kinetic models is the lack of kinetic parameters for many enzymatic reactions. Here, the authors introduce a framework to explore the catalytically optimal operating conditions of any complex enzyme m ...

Nature Portfolio2023

Precipitation, Characterization, Kinetic, and Thermodynamic Modelling of Synthetic C-S-H Systems (C-S-H, CASH, CSH+$)

Maya Nicole Harris

This thesis investigates the effects of aluminates, sulfates, and heterogeneous substrates on the nucleation and growth of synthetic calcium-silicate-hydrates (C-S-H) produced by dropwise precipitation. The use of synthetic C-S-H, separate from other cemen ...

EPFL2022

Temperature Dependent Properties of the Aqueous Electron

Alfredo Pasquarello, Jinggang Lan

The temperature-dependent properties of the aqueous electron have been extensively studied using mixed quantum-classical simulations in a wide range of thermodynamic conditions based on one-electron pseudopotentials. While the cavity model appears to expla ...

Wiley-VCH Verlag GmbH2022

Hydrodynamic synchronization and clustering in ratcheting colloidal matter

Ignacio Pagonabarraga Mora

Ratchet transport systems are widespread in physics and biology; however, the effect of the dispersing medium in the collective dynamics of these out-of-equilibrium systems has been often overlooked. We show that, in a traveling wave magnetic ratchet, long ...

AMER ASSOC ADVANCEMENT SCIENCE2022

Nonlinear electro-mechanical coupling and thermally stimulated currents in relaxor ferroelectrics

Lukas Riemer

In this work, the emergence of polarization and electro-mechanical coupling in Pb(Mg1/3Nb2/3)O3 and Pb(Mg1/3Nb2/3)O3 â PbTiO3 was investigated by means of thermally stimulated current, and nonlinear dielectric and electro-mechanical measurements. The pre ...

EPFL2022

Intrinsic Polarization Super Junctions: Design of Single and Multichannel GaN Structures

Elison de Nazareth Matioli, Catherine Erine, Luca Nela, Amirmohammad Miran Zadeh

Super junctions (SJs) have enabled unprecedented performance in Silicon power devices, which could be further improved by applying this concept to wide bandgap semiconductors like gallium nitride (GaN). Currently, polarization super junctions (PSJs) are th ...

2022

Modelling electronic transport in monocrystalline metal oxide gas sensors: from the surface kinetics to the experimental response

Roberto Guarino, Gianluca Piccinini

Gas sensing systems and devices based on metal oxides are widely spreading due to their high performance in terms of sensor response and relatively low costs. Despite several experimental studies, as well as molecular simulations, are available in the lite ...

2022

Uncertainty estimation for molecular dynamics and sampling

Michele Ceriotti, Venkat Kapil, Giulio Imbalzano, Edgar Albert Engel, Kevin Rossi, Yongbin Zhuang, Federico Grasselli

Machine-learning models have emerged as a very effective strategy to sidestep time-consuming electronic-structure calculations, enabling accurate simulations of greater size, time scale, and complexity. Given the interpolative nature of these models, the r ...

2021

The Pristine survey - XIV. Chemical analysis of two ultra-metal-poor stars

Pascale Jablonka, Carmela Lardo

Elemental abundances of the most metal-poor stars reflect the conditions in the early Galaxy and the properties of the first stars. We present a spectroscopic follow-up of two ultra-metal-poor stars ([Fe/H] < -4.0) identified by the survey Pristine: Pristi ...

OXFORD UNIV PRESS2021

Emergent nonlinear phenomena in a driven dissipative photonic dimer

Rui Ning Wang, Tobias Kippenberg, Kenichi Komagata, Hairun Guo, Junqiu Liu, Mikhail Churaev, Alexey Tikan

Collective effects leading to spatial, temporal or spatiotemporal pattern formation in complex nonlinear systems driven out of equilibrium cannot be described at the single-particle level and are therefore often called emergent phenomena. They are characte ...

NATURE RESEARCH2021

Synthesis of metal oxide photoanodes for water splitting using nanocrystals as precursors

Chethana Janardhana Gadiyar

Photoelectrochemical (PEC) water splitting devices are envisioned to play a key role in the societal transition towards sustainable energy sources. In this context, multinary metal oxide semiconductors are the most promising candidates for the role of phot ...

EPFL2020

Optoelectronic and magnetic properties induced by atomic defects in two-dimensional semiconductors

Alessio Scavuzzo

Two-dimensional (2D) materials have attracted increasing attention over the last decade owing to their remarkable mechanical, electrical and optical properties. Following the groundbreaking discovery of graphene, a plethora of other atomically-thin materia ...

EPFL2020

Numerical and experimental investigations on non-contacting seals for small-scale applications

Suresh Katuwal Chhetri

Dynamic non-contacting seals have been identified as the most appropriate sealing technology for reduced-scale and high-speed turbomachinery applications since they provide a clearance gap preventing rotor-to-seal contact during operation. Yet, any clearan ...

EPFL2020

Anisotropic exchange Hamiltonian, magnetic phase diagram, and domain inversion of Nd2Zr2O7

We present thermodynamic and neutron-scattering measurements on the quantum spin ice candidate Nd2Zr2O7. The parametrization of the anisotropic exchange Hamiltonian is refined based on high-energyresolution inelastic neutron-scattering data together with t ...

2019

Large impact of strain on the electro-optic effect in (Ba, Sr)TiO3 thin films: Experiment and theoretical comparison

Alexander Tagantsev

(001)-epitaxial (Ba0.5Sr0.5)TiO3 (BST) thin films with different magnitudes of compressive strain were fabricated on SrRuO3/SrTiO3 substrates by pulsed laser deposition, and their electro-optic (EO) properties were characterized by modulation ellipsometry ...

AMER INST PHYSICS2019