You are here
First experimental observation of the roton effect in metamaterials
Experiments conducted jointly by FEMTO-ST and KIT demonstrate the control of forward and backward wave propagation by adjusting the frequency.
The roton is a quasi-particle that satisfies an unusual dispersion relation for acoustic waves in superfluid Helium-4 at low temperatures. Two recent theoretical papers have shown that roton-like dispersion relations exist in periodic media or metamaterials. Experimental demonstration of the effect was however still lacking. A joint study published in SciencesAdvances by the Karlsruher Institut für Technologie and FEMTO-ST reports on the experimental observation of the roton effect in elastic and acoustic metamaterials.
The following figure shows a 3D view of the acoustic metamaterial examined by the French group.
Remarkably, continuous tuning is obtained, by a simple adjustment of the wavelength, from forward wave propagation to backward wave propagation, followed by a minimum of the dispersion relation that marks the effective presence of the roton at audible frequencies.
The study illustrates that using higher-order interactions, that are relatively easy to implement with elastic and acoustic waves, opens unprecedented experimental possibilities for modeling the dispersion of phonons and their interactions.
This work was highlighted on the website of the French National Centre for Scientific Research : see the article
Robotic assembly of the smallest house in the world
the handling and assembly capabilities of nanocomponents of the "μRobotex" platform make the buzz on the net and in the international press through the origami manufacturing of a micro-house at the end of an optical fiber whose dimensions are less than the diameter of a hair.Read more
International Day of Light 2018
Following the success of the International Year of Light, which highlighted the importance of light-based science and technology and generated more than 13,000 activities in 147 countries, UNESCO proclaimed May 16 as the International Day of Light.Read more
Enrico Rubiola honored at IFCS 2018
Enrico Rubiola will receive the W. G. Cady Award at the IFCS 2018 on May 24th.Read more
L'institut FEMTO-ST partenaire d'un programme européen Marie-Curie H2020 Innovative Training Networ
The department of Optics of the FEMTO-ST research institute in Besançon Read more
in France currently has a vacancy for 2 3-years Ph.D positions working in
the development of mid-infrared and ultraviolet supercontinuum fiber sources within the
FACS 2016 - The 13th International Conference on Formal Aspects of Component Software
The DISC department, organizer of the 13th International Conference on FACS.
Special issue of Comptes Rendus Physique on phononic crystals
The May 2016 issue of Comptes Rendus Physique (an international peer-reviewed journal of the French Academy of Sciences), is devoted to phononic crystals. This special issue was coordinated by Vincent Laude.
Paper prize at the international conference VPPC 2014
At the International IEEE "Vehicle Power and Propulsion Conference" conference held in Coimbra, Portugal from 27 to 30 October 2014, “Hybrid & Fuel Cell Systems” Research Team of Femto-ST Institute won the Paper Prize for the paper titled “Energy management of an hybrid electrical vehicule in degraded operation”
A book about flexible robotics co-written by Nicolas Chaillet
The objective of the book "Flexible Robotics: Applications to Multiscale Manipulations" is to provide those interested in the field of flexible robotics with an overview of several scientific and technological advances in the practical field of robotic manipulation.
Nonlinear Optics and Supercontinuum Symposium
A one day “Nonlinear Optics and Supercontinuum Symposium” will be held on Friday 20 September in the Amphi FEMTO in honour of Professor Chinlon Lin who will be here in Besançon during this time.