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MA: Fachverband Magnetismus
MA 52: Poster Magnetism III
MA 52.15: Poster
Donnerstag, 12. März 2026, 15:00–17:00, P4
Quantum Geometry of Magnons — •Sidhartha Chatterjee1, Andreas Haller1, Peter P. Orth2, and Thomas L. Schmidt1 — 1University of Luxembourg — 2Saarland University
We develop a theoretical framework for magnon dynamics in a one-dimensional antiferromagnetic Heisenberg chain that includes next-nearest-neighbour Dzyaloshinskii-Moriya interaction (DMI) and a position-dependent magnetic field applied along the easy axis. This combination leads to a spin spiral ground state. The collective excitations above the ground state are magnons, spin-1 bosonic modes. We perform the Holstein-Primakoff transformation to obtain the magnon Hamiltonian, which is quadratic in nature. For the diagonalisation, we use the Bogoliubov transformation, and we show that the quantum geometric tensor of magnons naturally exhibits symplectic structure. This geometric structure yields corrections to the semiclassical equations of motion for magnon wave packets, resulting in anomalous velocity terms and metric-driven contributions. Overall, the framework provides a systematic route for incorporating geometric effects and symplectic structure into magnon dynamics, where no particle number conserving framework exists, and offers a pathway for engineering transport phenomena in magnetic materials through the direct manipulation of the quantum geometry of their collective excitations.
Keywords: Quantum geometry; Quantum metric; Magnon; Symplectic structure; Antiferromagnet