Physikalisches Kolloquium: Prof. Dr. Paul H.M. van Loosdrecht – Probing quantum materials: Nonlinear THz spectroscopy

Titel: Probing quantum materials: Nonlinear THz spectroscopy

Abstract:
Non-linear THz spectroscopy has developed into a sensitive and effective method to probe electrodynamics and electronic properties of quantum materials. Very efficient THz high-harmonic generation in Dirac materials, such as graphene [1] and the 3D Dirac semimetal Cd3As2 [2], has been reported, originating from the linear dispersion in these materials. In superconductors, coupling of the THz field to the Higgs mode also leads to a pronounced non-linear THz response [3], as does the non-Fermi liquid state in CaRuO3 [4]. Apart from high-harmonic generation, the non-linear THz response can also provide insights into the coupling between for instance magnons and phonons in magnetically ordered materials, as is for instance found in antiferromagnetic CoF2 [5]. This contribution will present some of the recent achievements in this field, and discuss the underlying mechanisms leading to the non-linear THz response.

[1] H.A. Hafez, S. Kovalev, J.-C. Deinert, et al., Nature 561, 507 (2018).
[2] S. Kovalev, R.M.A. Dantas, S. Germanskiy, et al., Nat. Comm. 11, 2451 (2020).
[3] R. Shimano and N. Tsuji, Annu. Rev. Condens. Matter Phys. 11, 103 (2020).
[4] C. Reinhoffer, S. Esser, S. Esser, et al., Phys. Rev. Lett. 132, 196501 (2024).
[5] T.W.J. Metzger, K.A. Grishunin, C. Reinhoffer, et al., Nat. Comm. 15, 5472 (2024).

Sprecher / Speaker: Prof. Dr. Paul H.M. van Loosdrecht, Universität zu Köln
Kontakt / Contact: Prof. Dr. Daniele Fausti

Norbert Lindlein lädt Sie zu einem geplanten Zoom-Meeting ein.
Norbert Lindlein invites you to a planned Zoom meeting.

Thema: Physikalisches Kolloquium 2024
Zoom-Link: https://fau.zoom-x.de/j/61637094478?pwd=ZamJS845k8KM9DsTrUuWzwr6Jeiap4.1
Meeting-ID: 616 3709 4478, Kenncode: 567858