Publications associées à Réseau de Bravais

Mean value theorems for collections of lattices with a prescribed group of symmetries

Euclidean lattices are mathematical objects of increasing interest in the fields of cryptography and error-correcting codes. This doctoral thesis is a study on high-dimensional lattices with the motivation to understand how efficient they are in terms of b ...

EPFL2024

The rule of four: anomalous distributions in the stoichiometries of inorganic compounds

Nicola Marzari, Marnik Bercx, Carl Simon Adorf, Elena Gazzarrini

Why are materials with specific characteristics more abundant than others? This is a fundamental question in materials science and one that is traditionally difficult to tackle, given the vastness of compositional and configurational space. We highlight he ...

Nature Portfolio2024

Molecular intercalation in the van der Waals antiferromagnets FePS3 and NiPS3

Bruce Normand, Ying Chen, Sheng Xu, Shuo Li, Xiaoyu Xu, Zeyu Wang, Weiqiang Yu

We have performed electrochemical treatment of the van der Waals antiferromagnetic materials FePS3 and NiPS3 with the ionic liquid EMIM-BF4, achieving significant molecular intercalation. Mass analysis of the intercalated compounds, EMIMx-FePS3 and EMIMx-N ...

Amer Physical Soc2024

High-Resolution Modeling Without Computation Slowdown for PETALE in CROCUS

Andreas Pautz, Vincent Pierre Lamirand, Thomas Jean-François Ligonnet, Axel Guy Marie Laureau

In a collaboration between Ecole Polytechnique Fédérale de Lausanne (EPFL) and CEA, in the fall of 2020, the experimental Programme d’Étude en Transmission de l’Acier Lourd et ses Eléments (PETALE) was successfully carried out in the CROCUS reactor of EPFL ...

2024

Critical line of the triangular Ising antiferromagnet in a field from a C3-symmetric corner transfer matrix algorithm

Frédéric Mila, Samuel Louis Nyckees, Afonso Dos Santos Rufino, Jeanne Colbois

The corner transfer matrix renormalization group (CTMRG) algorithm has been extensively used to investigate both classical and quantum two-dimensional (2D) lattice models. The convergence of the algorithm can strongly vary from model to model depending on ...

Amer Physical Soc2023

Enhanced Leaching of Zinc Ferrite by the Formation of a Solid Solution With Magnetite in Hydrochloric Acid Solution

The high zinc and iron contents of electric arc furnace (EAF) dust in the forms of zinc ferrite (ZnFe2O4) and magnetite (Fe3O4) make it a valuable secondary source of these metals. ZnFe2O4 and Fe3O4 are known to form a solid solution at all compositions, a ...

SPRINGER2023

Atomic scale volume and grain boundary diffusion elucidated by in situ STEM

Johann Michler, Xavier Maeder, Amit Sharma, Laszlo Pethö

Diffusion is one of the most important phenomena studied in science ranging from physics to biology and, in abstract form, even in social sciences. In the field of materials science, diffusion in crystalline solids is of particular interest as it plays a p ...

Nature Portfolio2023

High-precision optical magnetometry using Nitrogen Vacancies in CVD diamond

Hossein Babashah

Sensing weak magnetic fields is a topic of great importance in basic science and technology due to its wide range of applications. In this context, solid-state and nanoscale quantum sensors are poised to revolutionize the sensing platforms due to their ult ...

EPFL2023

Periodic and Aperiodic NiFe Nanomagnet/Ferrimagnet Hybrid Structures for 2D Magnon Steering and Interferometry with High Extinction Ratio

Dirk Grundler, Sho Watanabe, Andrea Mucchietto, Shixuan Shan, Elif Nur Dayi, Vinayak Shantaram Bhat

Magnons, quanta of spin waves, are known to enable information processing with low power consumption at the nanoscale. So far, however, experimentally realized half-adders, wave-logic and binary output operations were based on few µm-long spin waves and re ...

Wiley2023

On the Mordell-Weil lattice of y(2) = x(3) + bx plus t(3n+1) in characteristic 3

Gauthier Leterrier

We study the elliptic curves given by y(2) = x(3) + bx + t(3n+1) over global function fields of characteristic 3 ; in particular we perform an explicit computation of the L-function by relating it to the zeta function of a certain superelliptic curve u(3) ...

SPRINGER INT PUBL AG2022

Square and rhombic lattices of magnetic skyrmions in a centrosymmetric binary compound

Jonathan White, Le Yu

Magnetic skyrmions are topologically stable swirling spin textures with particle-like character, and have been intensively studied as a candidate of high-density information bit. While magnetic skyrmions were originally discovered in noncentrosymmetric sys ...

Nature Research2022

Atomic-scale insights into the origin of rectangular lattice in nanographene probed by scanning tunneling microscopy

Shaoxian Li

We conducted atomic-scale scanning tunneling microscopy of a graphene nanosheet on graphite. In addition to a rhombus lattice representing the (root 3x root 3)R30 degrees superstructure, we resolved another quadrangle lattice similar to a rectangle in the ...

AMER PHYSICAL SOC2021

Molecular Origin of the Asymmetric Photoluminescence Spectra of CsPbBr3 at Low Temperature

Michael Graetzel, Ursula Röthlisberger, Ariadni Boziki, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin

CsPbBr3 has received wide attention due to its superior emission yield and better thermal stability compared to other organic-inorganic lead halide perovskites. In this study, through an interplay of theory and experiments, we investigate the molecular ori ...

2021

Diamond diffractive optics-recent progress and perspectives

Niels Quack, Gergely Huszka, Sichen Mi, Marcell Kristof Kiss

Diamond is an exceptional material that has recently seen a remarkable increase in interest in academic research and engineering since high-quality substrates became commercially available and affordable. Exploiting the high refractive index, hardness, las ...

WALTER DE GRUYTER GMBH2021

New Results in Integer and Lattice Programming

Christoph Hunkenschröder

An integer program (IP) is a problem of the form

\min \{f(x) : \, Ax = b, \ l \leq x \leq u, \ x \in \Z^n\}

, where

A \in \Z^{m \times n}

,

b \in \Z^m

,

l,u \in \Z^n

, and

f: \Z^n \rightarrow \Z

is a separable convex objective function. The problem o ...

EPFL2020

Nanostructured alloys light the way to silicon-based photonics

Anna Fontcuberta i Morral

Silicon used for electronics has a cubic crystal lattice, which makes the material unsuitable for photonics applications. A method for producing germanium and silicon-germanium alloys that have hexagonal lattices offers a solution. ...

NATURE PUBLISHING GROUP2020

Staggered flux state for rectangular-lattice spin-1/2 Heisenberg antiferromagnets

Henrik Moodysson Rønnow, Dmitri Ivanov, Bastien Dalla Piazza, Noore Elahi Shaik

We investigate the spin-1/2 Heisenberg model on a rectangular lattice, using the Gutzwiller projected variational wave function known as the staggered flux state. Using Monte Carlo techniques, the variational parameters and instantaneous spin-spin correlat ...

AMER PHYSICAL SOC2020

Structure:function relationships for thermal and light-induced spin-crossover in isomorphous molecular materials

Sergio Vela Llausi

Isomorphous [FeL2]BF4center dot solv and [FeL2]ClO4center dot solv (L = 4-{isopropylsulfanyl}-2,6-di{pyrazol-1-yl}pyridine; solv = MeNO2, MeCN, 0.67Me(2)CO or H2O) exhibit a variety of thermal spin-crossover (SCO) behaviours. This complexity exte ...

Royal Society of Chemistry2020

Multi-physical characterization of cellular ceramics for high-temperature applications

Ehsan Rezaei

The use of cellular ceramics in enhancing the performance of a high-temperature latent heat thermal energy storage unit was investigated. A detailed design methodology is presented, which consists of a combined analytical-numerical analysis followed by a m ...

EPFL2020

Two coupled chains are simpler than one: field-induced chirality in a frustrated spin ladder

Joël Mesot, Shuang Wang

Although the frustrated (zigzag) spin chain is the Drosophila of frustrated magnetism, our understanding of a pair of coupled zigzag chains (frustrated spin ladder) in a magnetic field is still lacking. We address this problem through nuclear magnetic reso ...

Nature Research2020