Terahertz Neel spin-orbit torques drive nonlinear magnon dynamics in antiferromagnetic Mn₂Au.

ABSTRACT: Antiferromagnets have large potential for ultrafast coherent switching of magnetic order with minimum heat dissipation. In materials such as Mn₂Au and CuMnAs, electric rather than magnetic fields may control antiferromagnetic order by Néel spin-orbit torques (NSOTs). However, these torques have not yet been observed on ultrafast time scales. Here, we excite Mn₂Au thin films with phase-locked single-cycle terahertz electromagnetic pulses and monitor the spin response with femtosecond magneto-optic probes. We observe signals whose symmetry, dynamics, terahertz-field scaling and dependence on sample structure are fully consistent with a uniform in-plane antiferromagnetic magnon driven by field-like terahertz NSOTs with a torkance of (150 ± 50) cm² A^-1

SUBMITTER: Behovits Y 

PROVIDER: S-EPMC10533548 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature