# Willkommen bei der AG Turchinovich

## New paper in Nature

Read our new paper in Nature on highly efficient THz frequency multiplication and harmonic generation in graphene.

H. A. Hafez, S. Kovalev, J.-C. Deinert, Z. Mics, B. Green, N. Awari, M. Chen, S. Germanskiy, U. Lehnert, J. Teichert, Z. Wang, K.-J. Tielrooij, Z. Liu, Z. Chen, A. Narita, K. Müllen, M. Bonn, M. Gensch, and D.Turchinovich, "Extremely efficient terahertz high-harmonic generation in graphene by hot Dirac fermions," Nature (2018)
DOI: 10.1038/s41586-018-0508-1

UDE press release

Feature in Nature Research Device and Materials Enginnering Community

Feature on phys.org

## Dmitry Turchinovich new professor at UDE

On 01.04.2017 Dmitry Turchinovich was appointed professor of experimental physics at the University of Duisburg-Essen.

Dmitry Turchinovich received M.Sc. in engineering and technology from St. Petersburg State Electrotechnical University and Ioffe Institute (1999), and Ph.D in physics from the University of Freiburg (2004). In 2005 - 2008 he was postdoc at Utrecht University and at Technical University of Denmark (DTU). From 2008 to 2014 Dmitry Turchinovich served on DTU faculty as an assistant and associate professor. In 2012 he joined Max Planck Institute for Polymer Research in Mainz, as the leader of Ultrafast dynamics & Terahertz spectroscopy research group.

In 2013 Dmitry Turchinovich was awarded with the European Union Career Integration Grant, and in 2016 he was designated senior member of the Optical Society of America. In 2015-2016 he held visiting professorship at Osaka University.

The research interests of Dmitry Turchinovich are ultrafast and terahertz dynamics of charge, lattice and spins in condensed matter systems, and general ultrafast science.

>> UDE press release

>> WAZ news feature

## Our research: Ultrafast terahertz condensed matter physics

Many elementary processes in electron, phonon and spin subsystems of a solid: e.g. momentum relaxation times of conduction electrons, lattice oscillation periods, spin-flip times and spin precession periods, occur on the ultrafast timescale of 10s of femtoseconds to a few picoseconds.

This timescale $\tau$ matches the terahertz (THz) frequency range, broadly defined as $\omega / 2\pi$ ~ 0.1 – 30 THz, and corresponding to the period of oscillation of electromagnetic fields in the range ~ 10 ps - 30 fs, or to the photon energies of ~ 0.4 – 120 meV. This facilitates the use of THz radiation for spectroscopy in a unique regime of $\omega \tau$ ~ 1, where the elementary ultrafast dynamics in condensed matter can be directly resolved.

Based on modern femtosecond laser technology, ultrafast THz spectroscopy allows one to directly probe equilibrium and non-equilibrium dynamics of charge, lattice and spins with temporal resolution down to 10s of femtoseconds, in a contact-free and non-destructive fashion.

The all-optical, contact-free nature of ultrafast THz spectroscopy in turn conveniently allows for investigation of ultrafast dynamics on the nano-scale. Systems such as e.g. nano-particles, organic and inorganic nanostructures (e.g. semiconductor quantum wells, dots and wires, graphene, carbon nanotubes, 2D materials, spin valves etc) can be routinely investigated, without the need to attach the contacts or embed markers of any sort. The information on such processes as e.g. linear and nonlinear nano-scopic motion of charge (both collective or single) on the femtosecond timescale; or the ultrafast dynamics of spins and lattice, can be directly and reliably inferred from the experiments. All this makes ultrafast THz spectroscopy an invaluable tool in modern nanoscience.