Publications associées à Sesquilinear forms over rings with involution

'Fraternal-twin' ferroelectricity: competing polar states in hydrogen-doped samarium nickelate from first principles

In ferroelectric switching, an applied electric field switches the system between two polar symmetry-equivalent states. In this work, we use first-principles calculations to explore the polar states of hydrogen-doped samarium nickelate (SNO) at a concentra ...

Iop Publishing Ltd2024

Band Gap Renormalization at Different Symmetry Points in Perovskites

Majed Chergui, Lijie Wang

Using ultrafast broad-band transient absorption (TA) spectroscopy of photoexcited MAPbBr3 thin films with probe continua in the visible and the mid- to deep-ultraviolet (UV) ranges, we capture the ultrafast renormalization at the fundamental gap at the R s ...

Amer Chemical Soc2024

Hierarchy of quasisymmetries and degeneracies in the CoSi family of chiral crystal materials

Yi-Chiang Sun, Philip Johannes Walter Moll, Chunyu Guo

In materials, certain approximated symmetry operations can exist in a lower-order approximation of the effective model but are good enough to influence the physical responses of the system, and these approximated symmetries were recently dubbed "quasisymme ...

AMER PHYSICAL SOC2023

Lattice packings through division algebras

Nihar Prakash Gargava

In this text, we will show the existence of lattice packings in a family of dimensions by employing division algebras. This construction is a generalization of Venkatesh's lattice packing result Venkatesh (Int Math Res Notices 2013(7): 1628-1642, 2013). In ...

SPRINGER HEIDELBERG2023

Simulating supercontinua from mixed and cascaded nonlinearities

Luis Guillermo Villanueva Torrijo, Tobias Herr, Victor Brasch, Thibault Voumard, Furkan Ayhan

Nonlinear optical frequency conversion is of fundamental importance in photonics and underpins countless of its applications: Sum- and difference-frequency generation in media with quadratic nonlinearity permits reaching otherwise inaccessible wavelength r ...

AIP Publishing2023

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

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

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

Byzantine consensus is Θ(n^2): the Dolev-Reischuk bound is tight even in partial synchrony!

Rachid Guerraoui, Seth Gilbert, Vincent Gramoli, Manuel José Ribeiro Vidigueira, Jovan Komatovic, Pierre Philippe Civit

The Dolev-Reischuk bound says that any deterministic Byzantine consensus protocol has (at least) quadratic (in the number of processes) communication complexity in the worst case: given a system with n processes and at most f < n/3 failures, any solution t ...

2023

Positive Definite Completions and Continuous Graphical Models

Kartik Waghmare

This thesis concerns the theory of positive-definite completions and its mutually beneficial connections to the statistics of function-valued or continuously-indexed random processes, better known as functional data analysis. In particular, it dwells upon ...

EPFL2023

Dynamic nuclear polarisation of 1H in Gd-doped In(OH)3

David Lyndon Emsley, Michael Allan Hope, Amrit Venkatesh, Yuxuan Zhang

Dynamic nuclear polarisation (DNP) of solids doped with high-spin metal ions, such as Gd3+, is a useful strategy to enhance the nuclear magnetic resonance (NMR) sensitivity for these samples. Spin diffusion can relay polarisation throughout a sample, which ...

Academic Press Inc - Elsevier Science2023

Exact quantum conformal symmetry, its spontaneous breakdown, and gravitational Weyl anomaly

Mikhail Chapochnikov, Anna Tokareva

The classical Lagrangian of the Standard Model enjoys the symmetry of the full conformal group if the mass of the Higgs boson is put to zero. This is a hint that conformal symmetry may play a fundamental role in the ultimate theory describing nature. The o ...

American Physical Society2023

Berry curvature dipole generation and helicity-to-spin conversion at symmetry-mismatched heterointerfaces

Peng Chen, Xupeng Yang

The Berry curvature dipole (BCD) is a key parameter that describes the geometric nature of energy bands in solids. It defines the dipole-like distribution of Berry curvature in the band structure and plays a key role in emergent nonlinear phenomena. The th ...

Nature Portfolio2023

Symmetry-Induced Singlet-Triplet Inversions in Non-Alternant Hydrocarbons

Anne-Clémence Corminboeuf, Jacob Terence Blaskovits, Marc Hamilton Folkmann Garner

Molecules with inversion of the singlet and triplet excited-state energies are highly promising for the development of organic light-emitting diodes (OLEDs). To date, azaphenalenes are the only class of molecules where these inversions have been identified ...

Wiley-VCH Verlag GmbH2023

Polarization-Controlled Chromo-Encryption

Olivier Martin, Hsiang-Chu Wang

The response of simple plasmonic nanorods to polarized illumination is studied in detail. Depending on the orientation of that polarization with respect to the symmetry axes of the nanostructure, a chiral response can occur, which can be analyzed through a ...

WILEY-V C H VERLAG GMBH2023

On the Grothendieck-Serre conjecture for classical groups

Eva Bayer Fluckiger

We prove some new cases of the Grothendieck-Serre conjecture for classical groups. This is based on a new construction of the Gersten-Witt complex for Witt groups of Azumaya algebras with involution on regular semilocal rings, with explicit second residue ...

WILEY2022

A finiteness result for p-adic families of Bianchi modular forms

Vlad Serban

We study p-adic families of cohomological automorphic forms for GL(2) over imaginary quadratic fields and prove that families interpolating a Zariski-dense set of classical cuspidal automorphic forms only occur under very restrictive conditions. We show ho ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Quasi-symmetry-protected topology in a semi-metal

Yi-Chiang Sun, Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke, Chunyu Guo

The concept of quasi-symmetry-a perturbatively small deviation from exact symmetry-is introduced and leads to topological materials with strong resilience to perturbations. ...

NATURE PORTFOLIO2022

On the commutativity of flows of rough vector fields

Maria Colombo, Riccardo Tione

In the class of Sobolev vector fields in R-n of bounded divergence, for which the theory of DiPerna and Lions provides a well defined notion of flow, we characterize the vector fields whose flow commutes in terms of the Lie bracket and of a regularity cond ...

ELSEVIER2022

Space-Efficient Representations of Graphs

Jakab Tardos

With the increasing prevalence of massive datasets, it becomes important to design algorithmic techniques for dealing with scenarios where the input to be processed does not fit in the memory of a single machine. Many highly successful approaches have emer ...

EPFL2022

Semiclassical methods in conformal field theories scrutinized by the epsilon-expansion

Gil Badel

Conformal Field Theories (CFTs) are crucial for our understanding of Quantum Field Theory (QFT). Because of their powerful symmetry properties, they play the role of signposts in the space of QFTs. Any method that gives us information about their structure ...

EPFL2022

Mismatched Decoding Reliability Function at Zero Rate

Marco Bondaschi

We derive an upper bound on the reliability function of mismatched decoding for zero-rate codes. The bound is based on a result by Komlos that shows the existence of a subcode with certain symmetry properties. The bound is shown to coincide with the expurg ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022