The point of this is explained in the paper.
- Please confirm the assumption 〈H〉 = -t∑〈ij〉σ nijσ + U∑j njj↑ njj↓ - μ ∑jσnjjσ
Where should the noise be scaled by repulsion?
The n matrices for spin up and spin down are stored in a single array N. The spin down elements go in N[0,:,:], spin up in N[1,:,:]. Thus the opposite spin is given by 1-spin.
The class physicalSystem has subclasses such as KuboOscillator and FermiHubbardGrid. These remember the physical parameters of the system, and calculate exact solutions for moments, if any are known.
The classstateEnsemble holds a numerical representation of system states, and context such as time and random processes. Subclasses compute derivatives and moments.
record stores the results of simulations, and tells the integration routines when to record them.