Comptes Rendus Physique

Mounir Teniou

Mehdi Ramdani

Ourouk Jawad

Thomas Julien

Stéphane Pannetrat

Lyazid Aberbour

On the measurement procedures for the assessment of the specific absorption rate (SAR) from MIMO cellular-equipment of fast varying relative phases

Guest editors

Damianos Agathangelou

Partha Pratim Roy

María del Carmen Marín

Nicolas Ferré

Massimo Olivucci

Tiago Buckup

Jérémie Léonard

Stefan Haacke

Sub-picosecond C$=$C bond photo-isomerization: evidence for the role of excited state mixing

Alaska Subedi

Light-control of materials via nonlinear phononics

Comptes Rendus
Physique
Johann Coraux and Xavier Marie
Foreword: Recent advances in 2D materials Physics
Volume 22, issue S4 (2021), p. 3-4
<https://doi.org/10.5802/crphys.99>
Part of the Special Issue: Recent advances in 2D material physics
Guest editors: Xavier Marie (INSA Toulouse, Université Toulouse III Paul Sabatier,
CNRS, France) and Johann Coraux (Institut Néel, Université Grenoble Alpes,
CNRS, France)
© Académie des sciences, Paris and the authors, 2021.
Some rights reserved.
This article is licensed under the
Creative Commons Attribution 4.0 International License.
http://creativecommons.org/licenses/by/4.0/
Les Comptes Rendus. Physique sont membres du
Centre Mersenne pour l’édition scientifique ouverte
www.centre-mersenne.org
Comptes Rendus
Physique
2021, 22, n S4, p. 3-4
https://doi.org/10.5802/crphys.99
Foreword / Avant-propos
Foreword: Recent advances in 2D materials
Physics
Avant-propos : Physique des matériaux
bidimensionnels
Johann Coraux∗, a and Xavier Marieb
a Univ. Grenoble Alpes, CNRS, Institut Néel, F-38000 Grenoble, France
b Univ. Toulouse, LPCNO (INSA, CNRS, UPS) F-31077 Toulouse, France
E-mails: johann.coraux@neel.cnrs.fr, marie@insa-toulouse.fr
Two-dimensional (2D) materials are fascinating objects for researchers with a wide variety of
possible applications. The 2010 Nobel Prize in Physics for graphene is certainly a very famous
milestone in their still young history, and the field keeps on renewing itself, at a pace that gives
no sign of slowing down, on the contrary.
Altogether, 2D materials host a plethora of intriguing effects and as such, have become
playgrounds for revisiting almost every branch or aspect of condensed matter physics, from
spin phenomena, superconductivity, photonics, to quantum coherence, electron correlation and
many-body effets, topology, and many more.
These materials can be isolated from naturally occurring bulk layered compounds or synthe-
sised from the bottom up, starting from atomic or molecular building-blocks. Quite remarkably,
they can be stacked on top of the other to form artificial materials at will, so-called van der Waals
heterostructures. Controlling their stacking sequence, one can engineer complex designer mate-
rials with e.g. strong electronic interactions and enhanced quantum effects.
The purpose of this special issue of Comptes Rendus Physique is to illustrate the latest advances
in this field of condensed matter physics, that is currently in full effervescence. Thousands
of scientific contributions are published every year in the condensed-matter physics branch
focusing on the investigation of these 2D materials, and several valuable topical reviews are
published on a yearly basis. Hence there cannot be any pretension for exhaustivity here, and
the present introduction will not engage in the delicate endeavour of a general perspective on
the physics of 2D materials. This special issue aims to illustrate the richness of these research
activities by presenting original results in several sub-fields.
∗Corresponding author.
ISSN (electronic) : 1878-1535 https://comptes-rendus.academie-sciences.fr/physique/
4 Johann Coraux and Xavier Marie
The field keeps on broadening, touching ever more research topics and involving an ever
growing number of scientists and engineers. Basic and applied research based on these materials
cross the boundaries of several disciplines, and an overview would obviously be too broad to
cover within a collection of articles such as in the present special issue. The special issue focuses
on recent advances in basic physics phenomena. These phenomena are inherited from the
atomic-scale structural order symmetries in 2D materials, and the resulting unique electronic,
optical, magnetic properties. The specific dimensionality of course plays a key role here. Together
with the 2D dimensionality, comes the effect of interfaces, which is prominent here, and makes
the van der Waals heterostructures of stacked 2D materials remarkably fertile fields of research
these days.
The articles address various kinds of 2D materials — graphene, superconductors, transition
metal (di)chalcogenides, hexagonal boron nitride — and their heterostructures, from experimen-
talists and theorists viewpoints. The special issue illustrates the variety of effects encountered in
these systems, especially: Electronic effects, related to defects or in the presence of correlation
and topology effects; Spin-related effects, in semiconductors and in the presence of the spin-orbit
interaction; Optical effects, how they relate to the electronic band structure of the materials and
with special attention to the physics of excitons influenced by the dimensionality, other excita-
tions, moirés or defects.
Acknowledgements
We thank all the contributors to this issue. They are forefront experts in their field and each bring
points of view we expect will be inspiring for the reader. We also thank Denis Gratias and the
editorial staff of Comptes Rendus Physique for their kind support and trust in this work.
C. R. Physique — 2021, 22, n S4, 3-4


Guillaume Cassabois

Adrien Rousseau

Christine Elias

Thomas Pelini

Phuong Vuong

Pierre Valvin

Bernard Gil

Hexagonal boron nitride: optical properties in the deep ultraviolet

Sha Han

Can-Li Song

Xu-Cun Ma

Qi-Kun Xue

Interface enhanced superconductivity in FeSe/SrTiO$_{3}$ and the hidden nature

Joe Wiart

Comptes Rendus
Physique
Joe Wiart
Foreword
Volume 22, issue S1 (2021), p. 1-2
<https://doi.org/10.5802/crphys.73>
Part of the Special Issue:URSI-France 2020 Workshop
Guest editor: Joe Wiart (LTCI, Télécom Paris, Institut Polytechnique de Paris,
Institut Mines-Télécom, France)
© Académie des sciences, Paris and the authors, 2021.
Some rights reserved.
This article is licensed under the
Creative Commons Attribution 4.0 International License.
http://creativecommons.org/licenses/by/4.0/
Les Comptes Rendus. Physique sont membres du
Centre Mersenne pour l’édition scientifique ouverte
www.centre-mersenne.org
Comptes Rendus
Physique
2021, 22, n S1, p. 1-2
https://doi.org/10.5802/crphys.73
URSI-France 2020 Workshop / Journées URSI-France 2020
Foreword
Joe Wiart a
a LTCI, Telecom Paris, Institut Polytechnique de Paris, Institut Mines Telecom, France
E-mail: Joe.wiart@mines.org
The year 2020 saw the commercial opening of fifth generation mobile phone networks. Since
the 1990s, generations of mobile networks have followed one another every 10 years. The second
generation, GSM, has democratized access to wireless mobile telephony. For the first time it
was possible to be far from home while remaining close to family. The third generation in the
2000s and then 4G in the 2010s enabled mobile Internet access, first at moderate speed then
at high/very high speed. These generations had in common that they had the human person
at the center of uses. With 5G, wireless networks will have been designed for the first time
from the outset with the aim of making possible both person-to-person, person-to-machine
and machine-to-machine communications, giving potential access to a plethora of data-based
services. The studies that have enabled the deployment of 5G are opening up new challenges.
The technological developments specific to this generation, the frequency rise, the foreseeable
evolutions that will require going beyond the framework of 5G towards the next generation, will
continue to stimulate significant efforts and new lines of research, involving the academic world
and industry. The deployment of this new generation also raises many societal questions linked
on the one hand to the energy consumption of 5G and on the other to electromagnetic waves and
associated exposure. The question of possible health impacts has given rise to numerous debates
where the perception of risk has been favored at the expense of an objective assessment of the
risk and of the actual exposure.
In view of all these challenges, opportunities and questions, URSI France decided in 2019 to
organize its 2020 annual scientific workshop on the theme of “Networks of the future: 5G and
beyond”, on the campus of Telecom Paris (Institut Polytechnique de Paris), Palaiseau, March
11–13, 2020.
This special issue is organized in 8 papers covering different aspects and challenges of future
networks. The first papers deal with the exposure induced by 5G system.
The paper entitled “In-situ evaluation of exposure induced by 5G antennas in the 3.4–3.8 GHz
band” is written by E. Conil and J. B. Agnani. It describes exposure measurements performed in
the vicinity of four pilot sites. The authors point out variations in the levels of exposure depending
on use of network resources and they propose a new indicator of exposure.
The second one, “Numerical modeling of downlink electromagnetic wave exposure generated
by 5G beamforming antennas”, authored by N. Noé and F. Gaudaire, analyses scenarios used for
numerical modeling of electromagnetic wave exposure to beamforming antennas. The authors
underline the influence of the environment around the antennas on the distribution of the
electric field.
ISSN (electronic) : 1878-1535 https://comptes-rendus.academie-sciences.fr/physique/
2 Joe Wiart
The third paper, entitled “On the Measurement Procedures for the Assessment of the Specific
Absorption Rate (SAR) from MIMO Cellular-Equipment of Fast Varying Relative Phases”, is au-
thored by M. Teniou, M. Ramdani, O. Jawad, T. Julien, S. Pannetrat and L. Aberbour. This paper
introduces a measurement methodology for the evaluation of the specific absorption rate (SAR)
of MIMO systems (multiple-input and multiple-output), in which the relative phases between
the antennas are rapidly changing over very short durations.
The fourth paper, entitled “Investigating Sub-THz PHY Layer for Future High-data-rate Wire-
less Backhaul”, is authored by G. Gougeon, Y. Corre, M. Z. Aslam, S. Bicaïs and J.-B. Doré and is
dedicated to future networks. It analyses the feasibility and characteristics of the in-street sub-
THz mesh backhauling. The study relies on a highly realistic simulation of the physical layer per-
formance, based on a detailed geographical representation and on ray-based propagation mod-
elling, for a new modulation scheme resistant to phase noise impairments.
The fifth paper, entitled “Multi-beam Modulated Metasurface Antenna for 5G Backhaul Appli-
cations at K-band”, by J. Ruiz-García, M. Faenzi, A. Mahmoud, M. Ettorre, P. Potier, Ph. Pouliguen,
R. Sauleau and D. González-Ovejero, explores the use of a new modulated metasurface (MTS) an-
tenna topology as a solution for wireless backhaul at K band. The authors show that employing a
modulated MTS, combined with the compactness of a pillbox approach, leads to a high-gain and
low-profile antenna.
The sixth paper “Bandpass NGD function design for 5G microwave signal delay synchroniza-
tion application” by S. Lalléchère, L. Rajaoarisoa, L. Clavier, R. Sanchez Galan and B. Ravelo, in-
troduces a design method of simple bandpass (BP) NGD topology. The authors show that the BP
NGD circuit can be useful for the improvement of phase linearity and group delay equalization
of future 5G microwave devices.
The seventh paper, entitled “Enhanced Integrated Multiband HPM Radiator, combining a
Hyperband Source with a High-Q Frequency Selective Surface” is authored by F. Albarracin-
Vargas, F. Vega, C. Kasmi, D. Martinez and L. Ole Fichte. This work presents advances on the
development of a resonant radiator and shows also that the system analysis methodology can
be applied to other FSS geometries.
The last paper, by T. Caillet and entitled “Compatibility between EESS (passive) in band
23.6–24 GHz and 5G in band 24.25–27.5 GHz”, describes the studies undertaken by several
European countries for the protection of frequency bands used by satellites for the observation
of the Earth. The elements provided in this document are the basis of the European position for
WRC-19 on the protection of passive EESS in 23.6–24 GHz.
We hope that this special issue offers you the possibilities to have a wide view on the future
networks, existing questions and challenges.
Joe Wiart
Président du Comité scientifique des
Journées URSI-France 2020
France
Joe.wiart@mines.org
C. R. Physique — 2021, 22, n S1, 1-2


Foreword

Eric Collet

Sylvain Ravy

Foreword: Ultrafast Phenomena in condensed matter physics

Ryo Fukaya

Nao Yamaya

Tadahiko Ishikawa

Shin-ya Koshihara

Yoichi Okimoto

Ken Onda

Akira Isayama

Takao Sasagawa

Kazumasa Horigane

Picosecond dynamics in layered cobalt perovskites studied by time-resolved Raman spectroscopy

Not a member yet

On the measurement procedures for the assessment of the specific absorption rate (SAR) from MIMO cellular-equipment of fast varying relative phases

Guest editors

Sub-picosecond C $=$ C bond photo-isomerization: evidence for the role of excited state mixing

Light-control of materials via nonlinear phononics

Guest editors

Hexagonal boron nitride: optical properties in the deep ultraviolet

Interface enhanced superconductivity in FeSe/SrTiO $_{3}$ and the hidden nature

Foreword

Foreword: Ultrafast Phenomena in condensed matter physics

Picosecond dynamics in layered cobalt perovskites studied by time-resolved Raman spectroscopy

2,036

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