Sergei Tretyakov

Sergei Anatolyevich Tretyakov (Серге́й Анато́льевич Третьяко́в; born in 1956) is a Russian-Finnish scientist, focused in electromagnetic field theory, complex media electromagnetics and microwave engineering.

He is currently a professor at Department of Electronics and Nanoengineering, Aalto University (former Helsinki University of Technology), Finland.

His main research area in recent years is metamaterials and metasurfaces from fundamentals to applications.

USSR in 1980 and 1987, respectively.

Professional career of Sergei Tretyakov started in 1980 at Radiophysics Department of Leningrad Polytechnic Institute, where he had been an engineer and junior researcher until 1986.

In 1986 he was promoted to the position of assistant professor and in 1989 to the position of associate professor.

In October 1988, Tretyakov had a 10-months-long research visit to Helsinki University of Technology (from 2010, Aalto University) according to the exchange program between

the Ministries of Education in Finland and Soviet Union.

During following 8 years, Tretyakov was affiliated with both Electromagnetics Laboratory of Helsinki University of Technology where he worked with Ismo Lindell and Ari Sihvola and

St. Petersburg State Technical University where he worked with Constantin Simovski.

In 1994 he was granted a Docent Diploma by the Ministry of Education of Russian Federation and in the following year he received Doctor of Sciences degree from St. Petersburg State Technical University, Russia.

Tretyakov visited CEA Cesta (French Alternative Energies and Atomic Energy Commission research centre), also affiliated with the Laboratory of Wave-Material Interactions in University of Bordeaux, for 6 months in 1994 as a visiting scientist.

In 1996, he was promoted to full professor position in St. Petersburg State Technical University, where he also became a director of Complex Media Electromagnetics Laboratory.

Tretyakov obtained his Full Professor Diploma in 1997 granted by the Ministry of Education, Russia.

In 1997, Tretyakov and his colleagues demonstrated that chiral effects (optical rotation and circular dichroism) can be achieved even with an infinitely thin composite layer without broken mirror symmetry.

From January 1999 until July 2000 Tretyakov was a visiting professor in Electromagnetics Laboratory of Helsinki University of Technology and in August 2000, he moved to the Helsinki University of Technology as a full professor of Radio Engineering.

However, due to the absence of materials with such properties in nature, wide interest to the backward wave media was generated only in the early 2000s, when the team of David R. Smith experimentally demonstrated first negative-index metamaterial.

This effect was subsequently named as planar chirality and independently discovered by the team of Nikolay I. Zheludev in 2003.

Possibility of existence of a backward wave medium, where electromagnetic waves propagate with anti-parallel phase and group velocities, was suggested by several scientists throughout the twentieth century: Arthur Schuster, Horace Lamb, Leonid Mandelstam, Victor Veselago, and others.

In 2003, Tretyakov and colleagues suggested an alternative way to achieve backward waves by using bianisotropic chiral materials.

In this case, it is not required to engineer negative permittivity and permeability, instead, one should just ensure proper chiral response of the material.

In the extreme case of so-called chiral nihility (when both relative permittivity and permeability are much smaller than the chirality parameter), two eigenwaves represent "forward" and "backward" circularly polarized waves with equal phase velocities.

The existence of backward waves in chiral media was independently suggested by John Pendry in 2004.

Inspired by the idea of transformation-optics based electromagnetic cloaking, Tretyakov's team developed an alternative realization of the same effect for cylindrical objects.

In contrast to the previous designs, Tretyakov's cloaking device exhibits significantly increased bandwidth and lower amount of dissipation loss.

He was the president of the European Virtual Institute for Artificial Electromagnetic Materials and Metamaterials (”Metamorphose VI”) and general chair of the Metamaterials Congresses from 2007 to 2013.

He is a fellow/member of many scientific associations such as IEEE, URSI, the Electromagnetics Academy, and OSA.

He is also an Honorary Doctor of Francisk Skorina Gomel State University.

Sergei Tretyakov has received the Engineer's degree and the Candidate of Sciences (PhD) degree in radiophysics from the Leningrad Polytechnic Institute,

Later on, as a visiting professor, he visited the Abbe Center of Photonics in Friedrich Schiller University Jena, Germany during June – July 2013, and the Department of Photonics Engineering in Technical University of Denmark during January - April 2013.

He educated 13 doctors of science.

Tretyakov has authored or co-authored more than 280 papers in refereed journals, 5 books, and 17 book chapters.

Tretyakov's research career started with his diploma thesis under supervision of Prof. V.A. Rozov.

The thesis was devoted to the problem of diffraction at an edge of dense planar arrays of metal wires, what is now referred as metasurfaces or two-dimensional metamaterials.

During the doctoral studies, Tretyakov worked on ferrite-based anisotropic layered structures under supervision of Prof. M.I. Kontorovich.

The first research visit to Helsinki University of Technology profoundly influenced his research interest, shifting it towards a novel and very promising direction of complex electromagnetic materials (now called metamaterials).

From this time forth Tretyakov actively works in this research direction with the main contributions listed below.

Tretyakov made important contributions to research of bianisotropic media.

Together with co-authors, he developed the general theory of electromagnetic waves interactions with bianisotropic materials and layers.

Moreover, Tretyakov proposed and experimentally characterized first non-reciprocal bianisotropic scatterers of two types: so-called Tellegen scatterer (named after Bernard D. H. Tellegen who suggested gyrator as a circuit element with equivalent electromagnetic response) and artificial "moving" scatterer (a composite based on such scatterers emulate response of a truly moving medium).