Publications associées à Coherent diffraction imaging

Phase Retrieval: From Computational Imaging to Machine Learning: A tutorial

Michaël Unser, Thanh-An Michel Pham, Jonathan Yuelin Dong

Phase retrieval consists in the recovery of a complex-valued signal from intensity-only measurements. As it pervades a broad variety of applications, many researchers have striven to develop phase-retrieval algorithms. Classical approaches involve techniqu ...

2023

Une version polyatomique de l'algorithme Frank-Wolfe pour résoudre le problème LASSO en grandes dimensions

Adrian Thibault Etienne Jarret, Matthieu Martin Jean-André Simeoni, Julien René Pierre Fageot

Nous nous intéressons à la reconstruction parcimonieuse d’images à l’aide du problème d’optimisation régularisé LASSO. Dans de nombreuses applications pratiques, les grandes dimensions des objets à reconstruire limitent, voire empêchent, l’utilisation des ...

2022

Phase Reconstruction of Low-Energy Electron Holograms of Individual Proteins

Klaus Kern, Stephan Rauschenbach, Sven Alexander Szilagyi, Hannah Julia Ochner

Low-energy electron holography (LEEH) is one of the few techniques capable of imaging large and complex three-dimensional molecules, such as proteins, on the single molecule level at subnanometer resolution. During the imaging process, the structural infor ...

AMER CHEMICAL SOC2022

Stochasticity helps to navigate rough landscapes: comparing gradient-descent-based algorithms in the phase retrieval problem

Lenka Zdeborová, Francesca Mignacco

In this paper we investigate how gradient-based algorithms such as gradient descent (GD), (multi-pass) stochastic GD, its persistent variant, and the Langevin algorithm navigate non-convex loss-landscapes and which of them is able to reach the best general ...

2021

Refinement for single-nanoparticle structure determination from low-quality single-shot coherent diffraction data

Christoph Bostedt, Christophe Nicolas

With the emergence of X-ray free-electron lasers, it is possible to investigate the structure of nanoscale samples by employing coherent diffractive imaging in the X-ray spectral regime. In this work, we developed a refinement method for structure reconstr ...

INT UNION CRYSTALLOGRAPHY2020

Monitoring Spontaneous Charge-Density Fluctuations by Single-Molecule Diffraction of Quantum Light

Jérémy Raymond Jean Maurice Rouxel

Homodyne X-ray diffraction signals produced by classical light and classical detectors are given by the modulus square of the charge density in momentum space vertical bar sigma(q)vertical bar(2), missing its phase, which is required in order to invert the ...

2019

Color neutral nanocomposite nickel-tantalum oxide for electrochromic windows

Andreas Schueler, Josef Andreas Schuler, Olivia Valérie Charlotte Bouvard

Electrochromic windows can darken on demand to limit the solar gains entering a building to reduce the risk of overheating, while preserving the view towards the exterior. Yet, the switching speed and contrast as well as the durability of commercial produc ...

IOP2019

Incommensurate atomic density waves in the high-pressure IVb phase of barium

Gervais Chapuis, Alla Arakcheeva, Philip Pattison, Vladimir Dmitriev

The host–guest structures of elements at high pressure discovered a decade ago still leave many open questions due to the lack of precise models based on full exploitation of the diffraction data. This concerns in particular Ba IV, which is stable in the r ...

Int Union Crystallography2017

Structural characterization of framework-gas interactions in the metal-organic framework Co-2(dobdc) by in situ single-crystal X-ray diffraction

Wendy Lee Queen, Miguel Gonzalez

The crystallographic characterization of framework-guest interactions in metal-organic frameworks allows the location of guest binding sites and provides meaningful information on the nature of these interactions, enabling the correlation of structure with ...

2017

Deformation behavior of nanoporous polycrystalline silver layers sintered by low temperature bonding: experiment and simulation

Saba Zabihzadeh

Integrated circuit packaging technology has become a prime design consideration for the develop-ment of electronic system concepts. One key issue is the bonding layer between chip and substrate. Currently, high-lead solder materials are being used, which a ...

EPFL2016