Bjarklev

Prof. Anders Overgaard Bjarklev, President the Technical University of Denmark

“Microwave and Photonic Metamaterials -The DTU Perspective”

The Technical University of Denmark (DTU) was founded in 1829 by the discoverer of the coupling between electricity and magnetism, Hans Christian Ørsted, and today electromagnetics constitutes a major research area encompassing antennas, microwave circuits, optical communication, photonics, remote sensing – and most recently the fascinating field of metamaterials. This plenary talk will overview major DTU contributions to microwave and photonic metamaterial science and propose visions for the future of metamaterials. The talk will touch upon several topics, e.g. the homogenization of periodically structured metamaterials and the retrieval of physically meaningful material parameters constitute a central topic in metamaterial science and one that continuously attract significant research interests. Single and double negative metamaterials facilitate resonances in sub-wavelength structures and the nature of these resonances has been demonstrated for several canonical geometries such as composite cylinders and spheres with ideal or real material models and illuminated by plane waves or point sources. Also, if light propagating in a material can be slowed down, its interaction with the material can be enhanced. Using photonic crystal defect waveguides, it was recently shown that this effect can be used to enhance the gain of an active material, e.g. quantum wells or quantum dots, opening the possibility of realizing ultra-compact slow-light enhanced optical amplifiers for photonic integrated circuits. Another topic will be structural colors: These offer an attractive approach to reduce the number of needed materials in a given product and it provides new perspectives for recycling and sustainability. Also, the role of optical metamaterials has evolved from pure exotic negative index cases and three-dimensional cloaking devices to more realistic examples, which have a strong potential for further development and photonic implementations. Among such examples ¬so called epsilon-near-zero materials, hyperbolic (indefinite) metamaterials, optical topological insulators (non-magnetic optical diodes) and metamaterials with enhanced quantum functions, e.g. exhibiting giant photogalvanic effect. The plenary speech will be based on the significant work and contributions of Lars-Ulrik Aaen Andersen, Samel Arslanagic, Olav Breinbjerg, Andrei Lavrinenko, Niels Asger Mortensen Jesper Mørk, Leif Katsuo Oxenløwe, and Anders O. Bjarklev, Technical University of Denmark


Lemme

Prof. Max Lemme, University of Siegen, Graphene-based Nanotechnology, Germany

“Graphene and related Two-Dimensional Materials: a Toolkit for Future Electronics Applications ?”

After an introduction of the state-of-the art in graphene and 2D materials and technology, this talk will discuss potential “More-than-Moore” applications for these materials. First, graphene field effect transistors (FETs) will be assessed for logic and radio frequency applications, followed by 2D FETs with semiconducting transition metal dichalcogenide (TMD) channels. Next, hot electron transistors with graphene components will be introduced that are projected to allow THz operation. Graphene is a broadband optoelectronic material that can operate from ultra-violet to THz radiation. TMDs are more limited in their spectral response, but show very high photon absorption. I will present examples for discrete photodetectors and modulators co-integrated with silicon photonics. Finally, the low mass of 2D materials makes them interesting for nanoelectromechanical systems. This will be discussed using the example of graphene membrane based piezoresistive pressure sensors.


Peruzzi

Prof. Giulio Peruzzi, Università di Padova e Accademia Galileiana di Scienze Lettere e Arti

“Trottole, vortici e campi. Maxwell e l'uso dell'analogia e della metafora nella scienza”

Se l’uso delle analogie e delle metafore accompagna l’intero percorso della scienza nata dalla rivoluzione scientifica, una piena consapevolezza della loro fondamentale funzione nella costruzione scientifica si acquisisce in fasi successive, e in particolare nel corso dell’Ottocento, il secolo nel quale la specializzazione acquista un ruolo sempre più significativo nell’ambito della crescita della conoscenza scientifica. È infatti proprio in una fase di crescente specializzazione che le analogie e le metafore diventano uno strumento importante per svelare connessioni inattese tra diversi settori e aprire nuove prospettive di ricerca. Molti sono gli scienziati ottocenteschi che ricorrono a questi ausili, ma probabilmente quello che con maggiore consapevolezza epistemologica e maggiore maestria ne sonda e sfrutta le grandi potenzialità è James Clerk-Maxwell. La stragrande maggioranza dei risultati da lui conseguiti in meno di trent’anni nella fisica, nella geofisica, nella fisiologia, nella metrologia, nell’ingegneria costituiscono ancora oggi le premesse di importanti campi di ricerca. Una delle ragioni della vastità e profondità della sua produzione scientifica risiede proprio nell’uso di analogie e metafore che gli permettono di individuare connessioni tra settori molto diversi tra loro, interpretando i risultati ottenuti in un certo ambito come elementi utili per orientarsi in ambiti anche molto diversi e meno conosciuti. Da questo punto di vista ripercorreremo alcuni dei momenti più significativi dell'opera di Maxwell, sottolineando la fecondità del suo approccio per gli sviluppi successivi della scienza e della tecnica.

Sessione plenaria