Speaker
Description
I will explain the Wang-Landau (WL) Monte Carlo method, comparing it with the traditional Metropolis algorithm. The WL method is particularly useful for calculating the density of states, from which we can derive important thermodynamic quantities like energy, entropy, specific heat, and free energy.
As a demonstration, I’ll examine the Ising model with both nearest-neighbor (J₁) and next-nearest-neighbor (J₂) interactions. For parameters J1=−2 and J2=−1, the system exhibits frustration due to the infinitely degenerate ground states.
Using the WL Monte Carlo method, we calculate the density of states, which allows us to determine the specific heat. Notably, as the system size L increases, the temperature at which a sharp peak in the specific heat occurs shifts toward zero, and the peak’s maximum height grows logarithmically.
