Quantum Spin Chain
Heisenberg model — spin waves, magnons, magnetic ordering
Sites N
20
J coupling
1.0
B field
0.0
Temperature
0.5
Reset
Flip spin
Heisenberg Model
H = −J Σ Sᵢ·Sᵢ₊₁ − B·Σ Sᵢ
J > 0: ferromagnetic
J < 0: antiferromagnetic
Spin waves (magnons) are collective excitations. At low T, long-range order emerges.
Magnons have dispersion ω(k) = 2JS(1−cos k)