Publications associées à Positivity bounds on electromagnetic properties of media

Publications associées (17)

CMOS-Compatible Antiferroelectric-Dielectric Capacitors for Multifunctional Energy Storage and Tunable Electronics

Hung-Wei Li, Mihai Adrian Ionescu, Igor Stolichnov, Niccolò Martinolli, Cyrille Masserey

This work presents a CMOS-compatible multilayer platform integrating energy storage and tunable varactor functionality within a compact system. By co-integrating antiferroelectric (AFE) and dielectric (DE) layers, the design achieves tunability up to 28%, ...

IEEE2025

Radiation Efficiency and Gain Bounds for Microstrip Patch Antennas

Anja Skrivervik

This article presents bounds on radiation efficiency and gain for microstrip patch antennas, demonstrating close alignment with the performance of classic antenna designs. These bounds serve as effective benchmarks for assessing antenna performance and eva ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2025

Cartesian and spherical multipole expansions in anisotropic media

Farhad Rachidi-Haeri, Marcos Rubinstein, Elias Per Joachim Le Boudec, Jose Felix Vega Stavro, Thomas Chaumont

The multipole expansion, a ubiquitous tool in a variety of physical problems, can be formulated in spherical and Cartesian coordinates. By constructing an explicit map linking both formulations in isotropic media, we discover a lack of equivalence between ...

Springer Science and Business Media LLC2025

Stored Energies and Q-Factor Expressed in Material Derivatives

Anja Skrivervik

Stored energies of radiating systems have generated research interest for several decades due to their relationship with Q-factor and fractional bandwidth. In this letter, material derivatives are used to provide a new interpretation of widely used stored ...

2024

Elastomers Based on Polynorbornene with Polar Polysiloxane Brushes for Soft Transducer Applications

Frank Nüesch, Yeerlan Adeli

Elastomers based on cross-linked bottlebrush polymers combine an extreme softness at low strains with a strain-stiffening effect, which makes them attractive as active components in dielectric elastomer actuators (DEA). Their main disadvantage concerns the ...

Wiley-VHCA AG2024

RG flows in de Sitter: C-functions and sum rules

Manuel Loparco

We study the renormalization group flow of unitary Quantum Field Theories on two-dimensional de Sitter (dS) spacetime. We prove the existence of two functions of the radius of dS that interpolate between the central charges of the UV and IR fixed points of ...

2024

Inversing the actuation cycle of dielectric elastomer actuators for a facial prosthesis

Yves Perriard, Yoan René Cyrille Civet, Paolo Germano, Thomas Guillaume Martinez, Stefania Maria Aliki Konstantinidi, Alexis Boegli, Quentin Philippe Mario De Menech

Dielectric Elastomer Actuators (DEAs) are a type of smart material described as compliant capacitors. They show impressive performances as soft actuators, such as a high strain and fast response. Nonetheless, replicating natural muscle function with DEAs h ...

Society of Photo-Optical Instrumentation Engineers (SPIE)2024

Nanoscale imaging and control of altermagnetism in MnTe

Jan Hugo Dil

Nanoscale detection and control of the magnetic order underpins a spectrum of condensed-matter research and device functionalities involving magnetism. The key principle involved is the breaking of time-reversal symmetry, which in ferromagnets is generated ...

NATURE PORTFOLIO2024

Toward Metantennas: Metamaterial-Based Antennas for Wireless Communications

Yuanyan Su

Antennas have historically been the most common electromagnetic (EM) technology for wireless communication systems. Antenna as hardware is entirely dependent on the EM properties of the materials used, mostly related to the permittivity and permeability. I ...

Ieee-Inst Electrical Electronics Engineers Inc2023

On the Applications of the Generalized Littlewood Theorem Concerning Integrals of the Logarithm of Analytical Functions to Elliptic Functions

Serguei Sekatski

Recently, we have established and used the generalized Littlewood theorem concerning contour integrals of the logarithm of analytical function to obtain new criteria equivalent to the Riemann hypothesis. Later, the same theorem was applied to calculate cer ...

MDPI2023

On-Demand Cross-Linkable Bottlebrush Polymers for Voltage- Driven Artificial Muscles

Frank Nüesch, Francis Owusu, Yeerlan Adeli

Dielectric elastomer actuators (DEAs) generate motion resembling natural muscles in reliability, adaptability, elongation, and frequency of operation. They are highly attractive in implantable soft robots or artificial organs. However, many applications of ...

AMER CHEMICAL SOC2023

Continuum mechanics from molecular dynamics via adiabatic time and length scale separation

Sara Bonella

We show how to construct, by exploiting adiabatic time and length scale separation between atomistic and continuum mechanics, a multiscale scheme for continuum dynamics free from macroscopic constitutive modeling. To do so, we introduce a new set of degree ...

2023

Modeling and analysis of miniaturized magnetorheological valve for fluidic actuation

Sofia Lydia Ntella

Fluidic actuation enables movement in a wide range of mechanical systems, from simple laboratory devices to more complex industrial machinery. Fluids are used to generate motion of mechanical pieces. The term "fluids" encompasses two types of technologies: ...

EPFL2023

Can we observe the ion-neutral drift velocity in prestellar cores?

Aris Evangelos Tritsis

Given the low-ionization fraction of molecular clouds, ambipolar diffusion is thought to be an integral process in star formation. However, chemical and radiative-transfer effects, observational challenges, and the fact that the ion-neutral drift velocity ...

2023

Nonlocally-resonant metamaterials

Aleksi Antoine Bossart

In this thesis, we unveil a third design path to manipulate elastic waves within architected media, distinct from the traditional phononic crystal and locally-resonant metamaterial concepts. The core innovation lies in the concept of nonlocal resonances, d ...

EPFL2023

Directed mean curvature flow in noisy environment

Martin Hairer

We consider the directed mean curvature flow on the plane in a weak Gaussian random environment. We prove that, when started from a sufficiently flat initial condition, a rescaled and recentred solution converges to the Cole-Hopf solution of the KPZ equati ...

Wiley2023

On the interaction of femtosecond laser pulses with layered dielectric materials

Ruben Ricca

Materials properties are strictly dependent on their microstructure. The internal symmetries and the disposition of the constituting atoms of a material, which depend on its crystallographic structure, greatly affect its response to mechanical, electromagn ...

EPFL2023