Concept

Matrice densité

Publications associées (109)

Tuning adatom mobility and nanoscale segregation by twin formation and polytypism

Anna Fontcuberta i Morral, Federico Matteini, Gözde Tütüncüoglu, Luca Francaviglia

Nanoscale variations in the composition of an AlxGa1−xAs shell around a GaAs nanowire affect the nanowire functionality and can lead to the formation of localized quantum emitters. These composition fluctuations can be the consequence of variations of crys ...

2018

Generalized resolution matrix for neutron spin-echo three-axis spectrometers

Thomas Keller, Felix Groitl

This article describes the energy resolution of spin-echo three-axis spectrometers (SE-TASs) by a compact matrix formalism. SE-TASs allow one to measure the line widths of elementary excitations in crystals, such as phonons and magnons, with an energy reso ...

INT UNION CRYSTALLOGRAPHY2018

On the entropy of fermionic reduced density matrices

Marius Christopher Lemm

The antisymmetry of a fermionic quantum state has a marked effect on its entanglement properties. Recently, Carlen, Lieb and Reuvers (CLR) studied this effect, in particular concerning the entropy of the two-body reduced density matrix of a fermionic state ...

2017

Phenylazide Hybrid-Silica - Polarization Platform for Dynamic Nuclear Polarization at Cryogenic Temperatures

Geoffrey Bodenhausen, Aurélien Bornet, Sami Jannin, Jonas Milani, Basile Vuichoud, David Benjamin Roger Antoine Gajan, David Baudouin

Hyperpolarization of NMR-active nuclei is key to gather high quality spectra of rare species and insensitive isotopes. We have recently established that silica-based materials containing regularly distributed nitroxyl radicals connected to the silica matri ...

Wiley-V C H Verlag Gmbh2017

Converse Bounds for Noisy Group Testing with Arbitrary Measurement Matrices

Volkan Cevher, Jonathan Mark Scarlett

We consider the group testing problem, in which one seeks to identify a subset of defective items within a larger set of items based on a number of noisy tests. While matching achievability and converse bounds are known in several cases of interest for i.i ...

Ieee2016

Learning-Based Compressive Subsampling

Volkan Cevher, Jonathan Mark Scarlett, Ilija Bogunovic, Yen-Huan Li, Luca Baldassarre, Baran Gözcü

The problem of recovering a structured signal

\mathbf{x} \in \mathbb{C}^p

from a set of dimensionality-reduced linear measurements

\mathbf{b} = \mathbf {A}\mathbf {x}

arises in a variety of applications, such as medical imaging, spectroscopy, Fourier o ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Detecting and Localizing Differences in Functional Time Series Dynamics: A Case Study in Molecular Biophysics

Victor Panaretos, Shahin Tavakoli

Motivated by the problem of inferring the molecular dynamics of DNA in solution, and linking them with its base-pair composition, we consider the problem of comparing the dynamics of functional time series (FTS), and of localizing any inferred differences ...

American Statistical Association2016

Limits on Sparse Support Recovery via Linear Sketching with Random Expander Matrices

Volkan Cevher, Jonathan Mark Scarlett

Linear sketching is a powerful tool for the problem of sparse signal recovery, having numerous applications such as compressive sensing, data stream computing, graph sketching, and routing. Motivated by applications where the \emph{positions} of the non-ze ...

2016

Energy correlations of photon pairs generated by a silicon microring resonator probed by Stimulated Four Wave Mixing

Matteo Galli, Christophe Marcel Georges Galland, Davide Grassani

Compact silicon integrated devices, such as micro-ring resonators, have recently been demonstrated as efficient sources of quantum correlated photon pairs. The mass production of integrated devices demands the implementation of fast and reliable techniques ...

Nature Publishing Group2016

Proximity Operators for Phase Retrieval

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We present a new formulation of a family of proximity operators that generalize the projector step for phase retrieval. These proximity operators for noisy intensity measurements can replace the classical "noise-free" projection in any projection-based alg ...

OSA2016

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