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Concept

Puits de potentiel

Publications associées (32)

High-order geometric integrators for the variational Gaussian wavepacket dynamics and application to vibronic spectra at finite temperature

Roya Moghaddasi Fereidani

Molecular quantum dynamics simulations are essential for understanding many fundamental phenomena in physics and chemistry. They often require solving the time-dependent Schrödinger equation for molecular nuclei, which is challenging even for medium-sized ...

EPFL2024

Charge-Transfer States in Organic Nanowires

Lucile Annie Chassat

Charge separation processes in organic semiconductors play a pivotal role in diverse applications ranging from photovoltaics to photocatalysis. Understanding these mechanisms, particularly the role of hybrid charge-transfer (CT) states, is essential for ad ...

EPFL2024

Heralded Spectroscopy: a new single-particle probe for nanocrystal photophysics

Edoardo Charbon, Claudio Bruschini, Samuel Burri, Arin Can Ülkü, Ivan Michel Antolovic

Semiconductor nanocrystals feature multiply-excited states that display intriguing physics and significantly impact nanocrystal-based technologies. Fluorescence supplies a natural probe to investigate these states. Still, direct observation of multiexciton ...

SPIE2023

Trapping Layers Prevent Dopant Segregation and Enable Remote Doping of Templated Self-Assembled InGaAs Nanowires

Anna Fontcuberta i Morral, Didem Dede, Nicholas Paul Morgan, Valerio Piazza

Selective area epitaxy is a promising approach to definenanowirenetworks for topological quantum computing. However, it is challengingto concurrently engineer nanowire morphology, for carrier confinement,and precision doping, to tune carrier density. We re ...

AMER CHEMICAL SOC2023

Copper-Phosphonate Lamella Intermediates Control the Shape of Colloidal Copper Nanocrystals

Raffaella Buonsanti, Jan Vávra, Dragos-Constantin Stoian, Valeria Mantella, Petru Pasquale Albertini, James Richard Pankhurst

Understanding the structure and behavior of intermediates in chemical reactions is key to developing greater control over the reaction outcome. This principle is particularly important in the synthesis of metal nanocrystals (NCs), where the reduction, nucl ...

2022

Imaging Nonradiative Point Defects Buried in Quantum Wells Using Cathodoluminescence

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Duncan Thomas Lindsay Alexander, Wei Liu, Wei Liu, Thomas Fjord Kjaersgaard Weatherley

Crystallographic point defects (PDs) can dramatically decrease the efficiency of optoelectronic semiconductor devices, many of which are based on quantum well (QW) heterostructures. However, spatially resolving individual nonradiative PDs buried in such QW ...

AMER CHEMICAL SOC2021

Work fluctuations in the active Ornstein-Uhlenbeck particle model

Francesco Cagnetta

We study the large deviations of the power injected by the active force for an active Ornstein-Uhlenbeck particle (AOUP), free or in a confining potential. For the free-particle case, we compute the rate function analytically in d-dimensions from a saddle- ...

IOP Publishing Ltd2021

Defect incorporation in In-containing layers and quantum wells: experimental analysis via deep level profiling and optical spectroscopy

Nicolas Grandjean, Jean-François Carlin, Camille Haller

Recent studies demonstrated that the performance of InGaN/GaN quantum well (QW) light emitting diodes (LEDs) can be significantly improved through the insertion of an InGaN underlayer (UL). The current working hypothesis is that the presence of the UL redu ...

IOP PUBLISHING LTD2021

Importance of Nuclear Quantum Effects for NMR Crystallography

Michele Ceriotti, Venkat Kapil, Edgar Albert Engel

The resolving power of solid-state nuclear magnetic resonance (NMR) crystallography depends heavily on the accuracy of computational predictions of NMR chemical shieldings of candidate structures, which are usually taken to be local minima in the potential ...

AMER CHEMICAL SOC2021

Molecular ordering effects in bulk and at lipid/water nanoscopic interfaces: A story of water, light, and order

Nathan Dupertuis

Water is ubiquitous on Earth, playing a critical role for a plethora of structures, processes and chemical reactions in nature. Its unique physicochemical properties originate mainly from its hydrogen bond network. Despite its recognized importance, many a ...

EPFL2021

Incidence of Quantum Confinement on Dark Triplet Excitons in Carbon Nanotubes

Ferenc Simon

The photophysics of single-wall carbon nanotubes (SWCNTs) is intensively studied due to their potential application in light harvesting and optoelectronics. Excited states of SWCNTs form strongly bound electron-hole pairs, excitons, of which only singlet e ...

2020

Thermomechanical Nanostraining of Two-Dimensional Materials

Jürgen Brugger, Giovanni Boero, Xia Liu, Ana Conde Rubio, Samuel Tobias Howell

Local bandgap tuning in two-dimensional (2D) materials is of significant importance for electronic and optoelectronic devices but achieving controllable and reproducible strain engineering at the nanoscale remains a challenge. Here, we report on thermomech ...

American Chemical Society (ACS)2020

Determination of the internal piezoelectric potentials and indium concentration in InGaN based quantum wells grown on relaxed InGaN pseudo-substrates by off-axis electron holography

Victor Carle Adrien Boureau

Micro light emitting diodes have been grown by metal organic vapor phase epitaxy on standard GaN and partly relaxed InGaNOS substrates with the purpose of incorporating higher concentrations of indium for identical growth conditions. Green emission has bee ...

2020

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

Ultrathin Junctionless Nanowire FET Model, Including 2-D Quantum Confinements

Farzan Jazaeri

In this paper, we develop an explicit model to predict the dc electrical behavior in ultrathin surrounding gate junctionless (JL) nanowire field-effect transistors (FETs). The proposed model considers 2-D electrical and geometrical confinements of carrier ...

2019

Two-dimensional Rashba metals: Unconventional low-temperature transport properties

Claudio Grimaldi

Rashba spin-orbit coupling emerges in materials lacking of structural inversion symmetry, such as heterostructures, quantum wells, surface alloys and polar materials, just to mention few examples. It yields a coupling between the spin and momentum of elect ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Isotope Dependence of Confinement in JET-ILW Deuterium and Hydrogen Plasmas

Henri Weisen

Heat, particle and momentum confinement in L- and H-mode in deuterium, hydrogen and in D/H mixtures have been investigated in JET with the ITER-like wall (JET-ILW). The paper expands on previous work [1,2] by presenting new results on heat, momentum and pa ...

IAEA2018

Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications

Jean-Claude Bünzli

Half a century after its initial emergence, lanthanide photonics is facing a profound remodeling induced by the upsurge of nanomaterials. Lanthanide-doped nanomaterials hold promise for bioapplications and photonic devices because they ally the unmatched a ...

WILEY-V C H VERLAG GMBH2018

Bimodal exciton-plasmon light sources controlled by local charge carrier injection

Klaus Kern, Anna Maria Roslawska, Christoph Grosse, Christopher Chih-Wan Loo Leon

Electrical charges can generate photon emission in nanoscale quantum systems by two independent mechanisms. First, radiative recombination of pairs of oppositely charged carriers generates sharp excitonic lines. Second, coupling between currents and collec ...

AMER ASSOC ADVANCEMENT SCIENCE2018

Propagating Polaritons in III-Nitride Slab Waveguides

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Gwénolé Jean Jacopin, Joachim Armand Simonne Ciers

We report on III-nitride waveguides with c-plane GaN/(Al,Ga)N quantum wells in the strong light-matter coupling regime supporting propagating polaritons. They feature a normal-mode splitting as large as 60 meV at low temperatures thanks to the large overla ...

American Physical Society (APS)2017