Work

Spin response of a magnetic monopole and quantum Hall response in topological lattice models through local invariants and light

Year: 2026

Type: article

Abstract: Here, we elaborate on and develop the geometrical approach introduced in Le Hur, Phys. Rep. 1104 (2025) between the magnetic monopole created from a radial field, quantum physics and topological lattice models through quantum phase transitions. We introduce an effective magnetic moment for a monopole when applying an additional source field along z -direction which also mediates the quantum phase transition. We present its relation with the transverse pumped quantum Hall current. The magnetic susceptibility can be introduced as a measure of the topological invariant i.e. it remains quantized within the topological phase until the transition. We show the relation with two-dimensional topological lattice models such as a honeycomb Haldane model in real space. We develop the theory and present a numerical analysis between local invariants in momentum space introduced from Dirac points, a real space correspondence and the responses to circularly polarized light. We develop the formalism for coupled-planes materials including the possibility of quantum spin Hall effect and address a relation between the Ramanujan infinite alternating series and an interface in real space with a topological number one-half.

Source: Comptes Rendus Physique

DOI: 10.5802/crphys.287

Authors: Karyn Le Hur, Andrea Baldanza

Institutions: Centre National de la Recherche Scientifique, Centre de Physique Théorique, Sapienza University of Rome

Language: English

Topic: Topological Materials and Phenomena

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funder: Studium Loire Valley-Institute for Advanced Studies

OpenAlex ID: W7204212409