Finite size errors

The standard way to simulate infinite systems is to use a finite box with periodic boundary conditions. As a result, if the size of the box is not large enough, one can have large errors due to finite size effects. These effects are very important in the proximity of a phase transition. In our simulations finite size effects are well under control, as is evident from Fig.3.4, and few tens of particles are enough to properly simulate the system in the thermodynamic limit.

Figure 3.4: Dependence of the energy $E$ measured in DMC simulation on the size of the system $N$