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Congratulations to our 2018 winner - Professor Mário G. Silveirinha

Professor Mário G. Silveirinha  

Professor Mário G. Silveirinha

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Time Reversal Symmetry Breaking with ‘Motion’


Propagation of electromagnetic waves - including microwaves, terrahertz waves and light - is inherently bi-directional in ‘normal’ material systems, a natural consequence of so-called ‘time-reversal symmetry’ deriving from the laws of elecgtromagnetism. Fortunately, in practice, there are several known techniques to circumvent this constraint to achieve “electromagnetic isolation” in engineered systems - critically important for such applications as mobile radio, radar, optical fibre communication networks.

Traditional solutions, though, are generally bulky, presenting difficulties for achieving the desired compact, modern, highly-integrated systems. This is particularly problematic at elevated frequencies, such as with terahertz and light-wave systems, which, owing to the short wavelengths involved, would otherwise allow the development of compact systems with very small dimensions.

However, in recent years, accompanied by the development of meta-material systems to allow practical realisation, there have been new developments in elecromagnetic theory - freed from the constraints of ‘normal, found in nature, materials properties’ - that offer the prospect of new approaches.

In his talk, Professor Silveirinha presented his vision of how the time-reversal symmetry can be broken with “mechanical motion”, such as by injecting a drift electric current into material. This provides the basis for further research his group will undertake supported by the IET A F Harvey prize funds. He showed how such solutions may enable the one-way propagation of terahertz waves totally immune to the undesired effects of back-scattering by obstacles, imperfections, and other deformations of the propagation path.


Professor Mário G. Silveirinha

Professor Mário G. Silveirinha received the Licenciado degree in Electrical Engineering from the University of Coimbra, Coimbra, Portugal, in 1998, and the Ph.D. degree in Electrical and Computer Engineering (with a minor in Applied Mathematics) from the Instituto Superior Técnico (IST), Technical University of Lisbon, Lisbon, Portugal, in 2003.

Currently, he is a Professor at the University of Lisbon, Portugal and a Senior Researcher at Instituto de Telecomunicações.

Mário Silveirinha is an IEEE Fellow with the citation “for contributions to the electrodynamics of metamaterials”. He is a founding editor of the APS journal Physical Review Applied.

He was a Visiting Professor at the University of Pennsylvania during several periods in 2004-2005 and 2010-2011, and a Chercheur CNRS en Physique at the University of Montpellier in 2017.

He is a junior member of the Academy of Sciences of Lisbon.

His research interests include electromagnetism, plasmonics and metamaterials, quantum optics, and topological effects ( web.tecnico.ulisboa.pt/mario.silveirinha/ )

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