2D Ising model Monte-Carlo (Metropolis) method
2D Ising model Monte-Carlo (Metropolis) method
Some Ferromagnetic Elements Some Paramagnetic Elements • Iron • Uranium • Nickel • Platinum • Cobalt • Aluminum • Gadolinium • Sodium • Dysprosium • Oxygen
Magnetic dipole–dipole interaction
Energy Magnetization
T<<Tc T ~Tc T>> Tc Almost at the Close to the phase High temperature ground state transition (no correlation between spins) Single large cluster Broad distribution All clusters of like of ordered spins of clusters spins are small with small clusters of opposite spins
Monte-Carlo method
Onsanger exact result H=0, kB=1, J=1 for critical temperature T~Tc=2.269 T<<Tc T>>Tc
The mean average over all configurations= Yang exact result for H=0 forr magnetization Ergodic principle After thermalization The mean average over all configurations= The mean time average over 1 configuration
The thermalization depends on the size of the lattice and the number of steps
http://iopscience.iop.org/article/10.1088/1367-2630/18/2/023008 A new look on the two-dimensional Ising model: thermal artificial spins amorphous Co68Fe24Zr8 NxN lattice , N=10487