Collective SW excitations in coupled nanodots

Collective spin-wave excitations in a two-dimensional array of coupled magnetic nanodots.
Roman Verba and Gennadiy Melkov, Vasil Tiberkevich and Andrei Slavin

Spin-wave absorption spectra (a) and mode
structure [(b) and (c)] in a magnetic dot array in a FM ground
state having one defect per 11 × 11 dots.

Phys. Rev. B 85, 014427 (2012)

Regions of stability of different ground
states of a magnetic dot array in zero applied field: above the solid blue line both the FM and the CAFM ground states are stable; below the solid blue line, but above the dashed red line only the
CAFM ground state is stable; below the dashed red line both FM and CAFM states are unstable and array switches to a state with in-plane direction of the dot static magnetization.