{"ID":23603865,"CreatedAt":"2026-09-18T06:00:06.305330393Z","UpdatedAt":"2026-09-18T06:00:06.305330393Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2609.20767","arxiv_id":"2609.20767","title":"Spacetime Dynamics of Altermagnetic Magnons","abstract":"Distinguishing altermagnetism from conventional ferromagnetism and antiferromagnetism typically relies on momentum-space probes. Here, we show that the real-space spreading of a localized spin excitation provides a distinctive dynamical fingerprint of altermagnetic order. Using linear spin-wave theory on a two-dimensional checkerboard lattice with nearest-neighbor and next-nearest-neighbor couplings J_1 and J_2, we demonstrate that finite J_2 produces direction-dependent magnon group velocities and splits the two magnon branches. The resulting propagation remains closer to that of an antiferromagnet than a ferromagnet, retaining an approximately circular outer wavefront, while the direction-dependent magnon velocities produce a pronounced cross-like spatial structure inside this front. We further show that changing the sign of J_2 to enter the unfrustrated regime (J_2\u003c0) increases the characteristic propagation velocities and interchanges the diagonal directions of enhanced propagation, corresponding to a pi/2 rotation of the anisotropic spatial pattern. These results establish spacetime dynamics as a complementary probe of altermagnetic magnons, providing a route to identifying unconventional magnetic order through real-space propagation patterns in solid-state and synthetic quantum systems.","short_abstract":"Distinguishing altermagnetism from conventional ferromagnetism and antiferromagnetism typically relies on momentum-space probes. Here, we show that the real-space spreading of a localized spin excitation provides a distinctive dynamical fingerprint of altermagnetic order. Using linear spin-wave theory on a two-dimensio...","url_abs":"https://arxiv.org/abs/2609.20767","url_pdf":"https://arxiv.org/pdf/2609.20767v1","authors":"[\"Ali Emami Kopaei\",\"Karthik Subramaniam Eswaran\",\"Krzysztof Wohlfeld\"]","published":"2026-09-17T17:46:01Z","proceeding":"cond-mat.str-el","tasks":"[\"cond-mat.str-el\",\"cond-mat.mtrl-sci\",\"cond-mat.quant-gas\"]","methods":"[]","has_code":false}