QuCoLiMa Talk – Peter Orth – Nonlinear interrogation of quantum materials: why higher order response tells you more

Speaker:

Peter Orth - Universität des Saarlandes

Title:

Nonlinear interrogation of quantum materials: why higher order response tells you more

Abstract:

The nonlinear response of quantum materials contains a wealth of information that is often hidden in the linear regime. Examples include second-harmonic generation (SHG) as a sensitive probe of electronic symmetry, and higher-order conductivities that provide insights into the quantum geometry of Bloch states and their Berry curvature distribution. Two-dimensional coherent THz and Raman spectroscopy are two other powerful nonlinear probes of low-energy excitations in quantum materials, which have recently become available in several labs. We review experimental progress and introduce an intuitive theoretical description of these methods in terms of Liouville quantum pathways. We then theoretically show how they can directly probe quasiparticle properties in the Kitaev honeycomb spin liquid and provide direct evidence for the emergence of localized Majorana excitations trapped by vison pairs.

Location:

Saarbrücken

All talks hybrid:

Mixture of on-site talks at the main sites of QuCoLiMa (Erlangen, Mainz, Saarbrücken) as well as online talks. Regardless of where the talks are given, they are livestreamed via Zoom and can be watched from home/office or cooperatively in the following meeting rooms:

- Erlangen: Livestream/Presentation in Lecture hall HF + open sandwiches in the foyer afterwards

- Saarbrücken: Livestream/Presentation in tba

- Mainz: Livestream/Presentation in tba

Zoom-Link:

http://www.qucolima.de/join-qucolima-talk

- - -

QuCoLiMa Talks are regular seminars of the collaborative research center TRR 306 QuCoLiMa (Quantum Cooperativity of Light and Matter), where (external) experts are invited to present their work.

More information at http://www.qucolima.de/talks