Publications associées à Groupe de papier peint

Accelerated Workflow for Antiperovskite-based Solid State Electrolytes

Andrea Fedrigucci, Ivano Eligio Castelli

We developed and implemented a multi-target multi-fidelity workflow to explore the chemical space of antiperovskite materials with general formula X(3)BA (X=Li, Na, Mg) and Pm-3m space group, searching for stable high-performance solid state electrolytes f ...

WILEY-V C H VERLAG GMBH2023

Outer automorphism anomalies

Brian Quinn Henning

We discuss anomalies associated with outer automorphisms in gauge theories based on classical groups, namely charge conjugations for SU(N) and parities for SO(2r). We emphasize the inequivalence (yet related by a flavor transformation) between two versions ...

Springer Nature2022

Low-Loss Anisotropic Image Polaritons in van der Waals Crystal alpha-MoO3

Sergejs Boroviks

Orthorhombic molybdenum trioxide (alpha-MoO3), a newly discovered polaritonic van der Waals crystal, is attracting significant attention due to its strongly anisotropic mid-infrared phonon-polaritons. At the same time, coupling of polariton with its mirror ...

WILEY-V C H VERLAG GMBH2022

Induced giant piezoelectricity in centrosymmetric oxides

Paul Muralt, Dragan Damjanovic, Mahmoud Hadad, Vasiliki Tileli, Lukas Riemer, Daesung Park

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle ...

American Association for the Advancement of Science2022

Crossover between distinct symmetries in solid solutions of rare earth nickelates

Duncan Thomas Lindsay Alexander, Bernat Mundet, Jean-Marc Triscone

A strong coupling of the lattice to functional properties is observed in many transition metal oxide systems, such as the ABO(3) perovskites. In the quest for tailor-made materials, it is essential to be able to control the structural properties of the com ...

2021

A stability theory beyond the co-rotational setting for critical wave maps blow up

Joachim Krieger, Shuang Miao

We exhibit non-equivariant perturbations of the blowup solutions constructed in [18] for energy critical wave maps into

\mathbb{S}^2

. Our admissible class of perturbations is an open set in some sufficiently smooth topology and vanishes near the light co ...

2020

Experimental studies of the equilibrium and out-of-equilibrium electronic structure of non-symmorphic topological materials

Gianmarco Gatti

Symmetry and topology are fundamental properties of nature. Mathematics provides us with a general framework to understand these concepts. On one side, symmetry describes the invariance properties of an object for specific transformations. On the other sid ...

EPFL2020

A Low-Parametric Rhombic Microstructure Family for Irregular Lattices

Francis Julian Panetta

New fabrication technologies have significantly decreased the cost of fabrication of shapes with highly complex geometric structure. One important application of complex fine-scale geometric structures is to create variable effective elastic material prope ...

2020

New refinement of the crystal structure of Zn(NH3)(2)Cl-2 at 100 K

Arnaud Magrez, Trpimir Ivsic

The crystal structure of [ZnCl2(NH3)(2)], diamminedichloridozinc, was reinvestigated at low temperature, revealing the positions of the hydrogen atoms and thus a deeper insight into the hydrogen-bonding scheme in the crystal packing. In comparison with pre ...

2019

Lattice formulation of axion inflation. Application to preheating

Daniel Garcia Figueroa, José Roberto Canivete Cuissa

We present a lattice formulation of an interaction phi/Lambda F (F) over tilde between an axion and some U(1) gauge sector with the following properties: it reproduces the continuum theory up to O(dx(mu)(2)) corrections, it preserves exact gauge invariance ...

IOP PUBLISHING LTD2019

Magnetic and dielectric order in the kagomelike francisite Cu3Bi(SeO3)(2)O2Cl

Helmuth Berger

We report a single-crystal neutron diffraction and inelastic neutron scattering study on the spin 1/2 cuprate Cu3Bi(SeO3)(2)O2Cl, complemented by dielectric and electric polarization measurements. The study clarifies a number of open issues concerning this ...

Amer Physical Soc2017

Complex magnetic incommensurability and electronic charge transfer through the ferroelectric transition in multiferroic Co3TeO6

Helmuth Berger, Yang Zhao

Polarized and unpolarized neutron diffractions have been carried out to investigate the nature of the magnetic structures and transitions in monoclinic Co3TeO6. As the temperature is lowered below 26 K long range order develops, which is fully incommensura ...

Springer Nature2017

A Theoretical Investigation of Topological Insulator Nanostructures

Naunidh Singh Virk

The topology of the electron wavefunctions in certain band insulators can give rise to novel topological phases. Materials harbouring such topological phases are termed topological insulators (TI). A gapped bulk electronic spectrum, described by a topologi ...

EPFL2016

Magnetic anisotropy in the frustrated spin-chain compound beta-TeVO4

Helmuth Berger

Isotropic and anisotropic magnetic behavior of the frustrated spin-chain compound beta-TeVO4 is reported. Three magnetic transitions observed in zero magnetic field are tracked in fields applied along different crystallographic directions using magnetizati ...

Amer Physical Soc2016

Medial axis transformation as a solid modeling representation method for computer aided design software

Paul Xirouchakis, Ian Anthony Stroud, Mihai-Bogdan Lazar, Florian Barras, Guillaume Goualard

A method for achieving a representation of an object within a data structure for a Computer Aided Design system employing a Medial Axis Transformation (MAT), the representation of the object comprising a set of adjacent bounded surface elements called MAT ...

2016

Post-deposition control of ferroelastic stripe domains and internal electric field by thermal treatment

Nava Setter, Silviu Cosmin Sandu, Ludwig Feigl, Monika Iwanowska

The dependence of the formation of ferroelastic stripe domain patterns on the thermal history is investigated by detailed piezoresponse force microscopy and X-ray diffraction experiments after and during annealing of tensile strained tetragonal Pb(Ti,Zr)O- ...

American Institute of Physics2015

Polarization properties and disorder effects in H-3 photonic crystal cavities incorporating site-controlled, high-symmetry quantum dot arrays

Elyahou Kapon, Alok Rudra, Benjamin Dwir, Pascal Gallo, Alessandro Surrente, Marco Felici

We report on the effects of optical disorder on breaking the symmetry of the cavity modes of H-3 photonic crystal cavities incorporating site-controlled pyramidal quantum dots (QDs) as the internal light source. The high in-plane symmetry of the polarizati ...

Amer Inst Physics2015

Symmetries and optical transitions of hexagonal quantum dots in GaAs/AlGaAs nanowires

Marc-André Dupertuis

We investigate the properties of electronic states and optical transitions in hexagonal GaAs quantum dots within Al0.3Ga0.7As nanowires, grown in axial direction [111]. Such dots are particularly interesting due to their high degree of symmetry. A streamli ...

Amer Physical Soc2015

An indiscrete Bieberbach theorem: from amenable CAT$(0)$ groups to Tits buildings

Nicolas Monod

Non-positively curved spaces admitting a cocompact isometric action of an amenable group are investigated. A classification is established under the assumption that there is no global fixed point at infinity under the full isometry group. The visual bounda ...

2015

Wave propagation in periodic buckled beams

Florian Paul Robert Maurin

Folding of the earth's crust, wrinkling of the skin, rippling of fruits, vegetables and leaves are all examples of natural structures that can have periodic buckling. Periodic buckling is also present in engineering structures such as compressed lattices, ...

EPFL2015