Optically induced non-linear magnetotransport in compensated magnets (B12[A10])

• Subject Area: Experimental Condensed Matter Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314695032

We recently discovered the quantum metric nonlinear anomalous Hall effect (nl-AHE) in antiferromagnets preserving combined parity and time-reversal symmetry (PT-AFs). It arises from electric field-induced Berry curvature and correlates with the antiferromagnetic order by reversing sign upon Néel vector inversion. Project B12 extends the nl-AHE to the optical regime, where it is predicted as a transverse to the Néel vector-oriented DC photocurrent driven by dipole transitions. Besides demonstrating this new effect in PT-AFs, we will study thin films of AF Weyl semimetals and altermagnets with externally induced broken P-symmetry.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1277: Emergent Relativistic Effects in Condensed Matter: From Fundamental Aspects to Electronic Functionality
• Applicant Institution: Universität Regensburg
• Project Heads: Professor Dr. Christian Back, until 12/2025; Dr. Matthias Kronseder, since 1/2026; Professor Dr. Jörg Wunderlich