Can alps can calculate the current correlation function for the fermionic hubbard model model for say two site. I have been using alps to calculate cahrge coorelation function
the charge correlation function is
< n_i n_j > = < c_i^+ c_i c_i^+ c_i >
where as the current correlation function is
< j_i j_j > = < c_i^+ c_j c_k^+ c_l >
see the changing indexes.
If it is possible then send me the program statement
Best regards
Khalid Loane