Huber group

Quantum cascade laser turns extremely nonlinear

Collaborating with partners from Germany, France, UK and Sweden we observed high-order terahertz nonlinearities directly in a free-running quantum cascade laser. With field-resolved two-dimensional spectroscopy we revealed up to eight-wave-mixing processes in a regime of negative absorption as well as the laser’s sub-cycle gain dynamics. High-order nonlinearities of this kind have the potential for various future applications, ranging from efficient intracavity frequency conversion and mode proliferation to passive mode locking.

The results have been published in Light: Science & Applications.... more

Columbus research grant for former team member Prof. Chaw-Keong Yong

The Ministry of Science and Technology of Taiwan has awarded our former team member and close collaborator Chaw-Keong Yong, who was recently appointed assistant professor at National Taiwan University, with the Columbus research grant. This fellowship recognises his work on 2D quantum materials and ultrafast optical spectroscopy as well as his extensive collaborative works with scientists across the world. The grant provides Prof. Chaw-Keong Yong with the opportunity to establish a competitive research group exploring quantum optoelectronic properties of atomically thin materials using ultrafast optical microscopy.

"Kulturpreis Bayern" for Dr. Fabian Mooshammer

Dr. Fabian Mooshammer has received the "Kulturpreis Bayern" for his PhD Thesis "Multi-terahertz nanotomography of van der Waals quantum materials". The prize honours people who enrich our society with their commitment, their work and their enthusiasm for art, culture and science.... more

Topological high-harmonic generation

Together with the groups of Klaus Richter (UR), Ferdinand Evers (UR), Ulrich Höfer (University of Marburg) and collaborators from the Novosibirsk State University, we discovered a novel generation mechanism of high-order harmonics in the surface state of a topological insulator. When quasi-relativistic electrons are accelerated through the Dirac point by an intense lightwave, they abruptly reverse their velocity allowing for purely non-integer high-harmonic generation. The lightwave-driven currents reveal intriguing aspects of the quantum mechanical nature of electrons in topological matter.

Press release (idw) in German
Press release (idw) in English

The results have been published in Nature.... more

Ultrafast terahertz nanoscopy: Coverstory in Nature Photonics

In collaboration with the group of Jaroslav Fabian (UR) and together with Tyler Cocker and Jessica Boland, we implemented a novel concept to map out ultrafast interlayer tunneling and recombination dynamics of excitons in van der Waals heterostructures in a contact-free manner. The new technique provides spatiotemporal access to tunnelling processes in insulating, conducting, or superconducting systems, on nanometer length and femtosecond time scales, conceptually bridging the gap between near-field microscopy and light-wave driven STM.

Press release (idw) in German
Press release (idw) in English

The results have been published in Nature Photonics. ... more