Magnons

1-D ferromagnetic magnons

1-D antiferromagnetic magnons

3-D low temperature limit

bcc ferromagnetic magnons

Equations of motion in mean field theory

$\hbar\frac{dS_p^x}{dt}= 2JS (2S_{p}^y-S_{p-1}^y-S_{p+1}^y )$
$\hbar\frac{dS_p^y}{dt}= -2JS (2S_{p}^x-S_{p-1}^x-S_{p+1}^x )$
$\hbar\frac{dS_p^z}{dt}= 0$

Eigenfunction solutions

Dispersion relation


Density of states D(ω)

Energy spectra1 density

Internal energy

Helmholtz free energy

Entropy

Specific heat