Magnons & Spin Waves (Holstein-Primakoff)

Spin waves in a 1D ferromagnetic chain. Dispersion ω(k) = 4JS(1−cos ka). Holstein-Primakoff bosons quantize deviations from the ordered state. Bose-Einstein distribution gives thermal magnon populations.

Exchange J (meV): 1.0

Spin S: 1.0

Temperature (K): 50

Wave mode k·a/π: 0.25

ω(k) at selected k—

⟨n_k⟩ (Bose-Einstein)—

Bandwidth 4JS—

k_B T / ω_max—