Light-induced odd-parity altermagnets on dimerized lattices

Abstract: Altermagnets are an emerging class of collinear magnets with momentum-dependent spin splitting and zero net magnetization. These materials can be broadly classified into two categories based on the behavior of spin splitting at time-reversal-related momenta: even-parity and odd-parity altermagnets. While even-parity altermagnets have been thoroughly investigated both theoretically and experimentally, the systems capable of hosting odd-parity altermagnetism remain largely unexplored. In this work, we demonstrate that circularly polarized light dynamically converts collinear PT-symmetric antiferromagnets on dimerized lattices into odd parity p-wave altermagnets. Because of the underlying Dirac band structure of the dimerized lattice, we find that the resulting p-wave altermagnets can realize Chern insulators (2D) and Weyl semimetals (3D) under appropriate drive conditions. Our findings demonstrate that collinear antiferromagnets on dimerized lattices provide ideal platforms to investigate the dynamical generation of odd-parity altermagnetism.