Publications associées à Single acquisition electrical property mapping based on relative coil sensitivities: A proof-of-concept demonstration

Ultrabroadband sound control with deep-subwavelength plasmacoustic metalayers

Hervé Lissek, Romain Christophe Rémy Fleury, Stanislav Sergeev

Controlling audible sound requires inherently broadband and subwavelength acoustic solutions, which are to date, crucially missing. This includes current noise absorption methods, such as porous materials or acoustic resonators, which are typically ineffic ...

Nature Research2023

Metamaterial graphene photodetector with bandwidth exceeding 500 gigahertz

Michael Baumann, Yesim Koyaz

Although graphene has met many of its initially predicted optoelectronic, thermal, and mechanical properties, photodetectors with large spectral bandwidths and extremely high frequency responses remain outstanding. In this work, we demonstrate a >500 gigah ...

American Association for the Advancement of Science2023

Microwave Metalens Antennas

Yuanyan Su, Teng Li

Recently, there has been growing interest in the use of metamaterial (MTM)-based lenses, also known as metalenses, as innovative antenna technology. Increasingly widespread applications of metalenses in modern microwave communication and sensing systems ha ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Plasma-based Electroacoustic Actuator for Broadband Sound Absorption

Stanislav Sergeev

Environmental noise, mostly related to human activities, has an immense impact on public health. The development of noise reduction technologies is paramount in addressing this problem. Because of practical and economic reasons, a compact, broadband, light ...

EPFL2022

Effect of mechanical nonlinearity on the electromagnetic response of a microwave tunable metamaterial

Taha Goudarzi, Romain Christophe Rémy Fleury, Bakhtiyar Orazbayev, Rayehe Karimi Mahabadi

Tunable metamaterials functionalities change in response to external stimuli. Mechanical deformation is known to be an efficient approach to tune the electromagnetic response of a deformable metamaterial. However, in the case of large mechanical deformatio ...

IOP Publishing Ltd2022

Spectral analysis for transmission eigenvalue problems with and without the complementing conditions

Jean Louis-Alexandre Fornerod

The interior transmission eigenvalue problem is a system of partial differential equations equipped with Cauchy data on the boundary: the transmission conditions. This problem appears in the inverse scattering theory for inhomogeneous media when, for some ...

EPFL2022

Emergent order in hydrodynamic spin lattices

Alexis Marie Frederic Goujon, John Bush

Macroscale analogues(1-3) of microscopic spin systems offer direct insights into fundamental physical principles, thereby advancing our understanding of synchronization phenomena(4) and informing the design of novel classes of chiral metamaterials(5-7). He ...

NATURE PORTFOLIO2021

Microwave or millimeter wave passive components or devices

Maliheh Khatibi Moghaddam, Romain Christophe Rémy Fleury

A passive device comprising a hollow waveguide including first and second wall structures extending in a guiding direction, an interconnecting base extending between the wall structures and an enclosure extending between the wall structures, the enclosure ...

2021

Metasurfaces for label-free biosensing mid-infrared optics and active photonic devices

Aleksandrs Leitis

Novel two-dimensional metamaterials, known as metasurfaces, have emerged as a breakthrough platform for controlling electromagnetic wave properties at the nanoscale. These metasurfaces consist of subwavelength nanoantennas or so-called meta-atoms, which ca ...

EPFL2021

Electromagnetic waves under nonstationary conditions, the connection with parity-time symmetry and studies on resonant systems

Theodoros Koutserimpas

In this thesis, the electromagnetic wave propagation is studied in nonstationary-medium scenarios. The electromagnetic fields under material time-modulation are shown to conserve their momentum but not their energy. The mathematical foundations and analysi ...

EPFL2021

Cloaking property of a plasmonic structure in doubly complementary media and three-sphere inequalities with partial data

Hoài-Minh Nguyên

We investigate cloaking property of negative-index metamaterials in the time-harmonic electromagnetic setting for the so-called doubly complementary media. These are media consisting of negative-index metamaterials in a shell (plasmonic structure) and posi ...

2020

Hermitian formulation of multiple scattering induced topological phases in metamaterial crystals

Romain Christophe Rémy Fleury, Nadège Sihame Kaïna

In this article we develop an analog to the SSH model in tight-binding chains of resonators and an innovative Hermitian matrix formulation to describe the topological phases induced by multiple scattering at subwavelength scales in one-dimensional structur ...

2020

Locating Transient Directional Sources in Free Space Based on the Electromagnetic Time Reversal Technique

Farhad Rachidi-Haeri, Marcos Rubinstein, Qi Li

Traditional location methods such as time of arrival and direction of arrival have been widely used to locate transient radiation sources. However, these approaches neglect the directional radiation pattern of the sources. Locating directional sources is a ...

2020

Analogue computing with metamaterials

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad

Despite their widespread use for performing advanced computational tasks, digital signal processors suffer from several restrictions, including low speed, high power consumption and complexity, caused by costly analogue-to-digital converters. For this reas ...

2021

Robust wave transport at subwavelength scale with chiral metamaterials

Romain Christophe Rémy Fleury, Nadège Sihame Kaïna, Bakhtiyar Orazbayev

Rapid progress in all types of communication systems imposes each time more strict requirements on the communication devices, requiring having the overall device's size as small as possible, but also increasing the demands on the robustness of the transmis ...

IEEE2019

Non-reciprocal manipulation of subwavelength fields in locally-resonant metamaterial crystals

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad, Nadège Sihame Kaïna

Locally-resonant metamaterial crystals are artificial materials built from small spatially-local resonant inclusions arranged periodically at subwavelength scale. Unlike conventional continuous metamaterials, for which spatial dispersion originates mostly ...

2020

Acoustic Supercoupling in a Zero-Compressibility Waveguide

Seyyed Hussein Seyyed Esfahlani

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety of applications. In electromagnetics, zero-permittivity metamaterials have been used to enhance the coupling of energy in a ...

2019

The invisibility via anomalous localized resonance of a source for electromagnetic waves

Hoài-Minh Nguyên

We investigate the invisibility via anomalous localized resonance of a general source in anisotropic media for electromagnetic waves. To this end, we first introduce the concept of doubly complementary media in the electromagnetic setting. These are media ...

SPRINGER INTERNATIONAL PUBLISHING AG2019

Active Times for Acoustic Metamaterials

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad

Initially proposed to achieve strong noise isolation levels beyond the mass-density law, acoustic metamaterials (AMMs) have now overturned the conventional views in all aspects of sound propagation and manipulation. In fact, within the last two decades, th ...

2019

Gain enhancement of circular waveguide antennas using near-zero index metamaterials

Kosmas Tsakmakidis, Foziyeh Sohrabi, Ershad Mohammadi

In this article, a rigorous analytical methodology is introduced for designing near-zero refractive index metamaterials (NZIMs). Our proposed NZIM media is realized by three stacked layers of perforated metallic surfaces, each layer composed of a fishnet-l ...

WILEY2019