Workshop 2025: Topological inverse Faraday effect: Optical Hopfion interacting with matter

Session Information

Location: Lecture room F3213 - 14
Day: Wednesday, 14 May
Time: 18:00 - 19:00
Chairperson: -

Presentation Details

Presentation Type: Poster presentation
Title: Topological inverse Faraday effect: Optical Hopfion interacting with matter
Abstract: Control and manipulation of quantum materials is of paramount significance, both for fundamental characterization and for quantum technologies. Among others, light-matter interaction has recently gained traction because both optical counterpart of solid-state phenomena and emergent effects can be investigated.

We extend this paradigm to 3D topological optical quasiparticle i.e. optical Hopfion (oHop) - a knotted structure presenting robust topological protection, resolution on ultrafast time-scales, localization on nanometer-scale - as novel source to probe and regulate properties and phases of matter.

We show a first instance of OHop-matter coupling: an oHop traveling through a non-magnetic material induces a net effective magnetization, that is now promoted to be topologically quantized in virtue of the linking number (Hopf index) classifying the oHop source. By relating the induced magnetization to the Hopf index, we identify the topologically quantum inverse Faraday effect (IFE). This optical response is obtained without constraints on the material but only by introducing topological light.
We conclude with a demonstration of the topologically quantized IFE compared to the standard IFE for a typical magneto-optical material like TGG.

Presenter

Dr Emma Minarelli
Chalmers University of Technology | Sweden

Authors

1. Minarelli, Emma | Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
2. Geilhufe, R. Matthias | Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden