create solvers and interface modules

Co-authored-by: Johanna Zijderveld

codes/utils.py

@@ -68,7+68,7 @@
         row, col = np.array([*product(row, col)]).T
         try:
             for arg in inspect.getfullargspec(val).args:
                 _params = {}
                 if arg in params:
                     _params[arg] = params[arg]
             val = val(site, **_params)
@@ -96,7+96,7 @@
         row, col = np.array([*product(row, col)]).T
         try:
             for arg in inspect.getfullargspec(val).args:
                 _params = {}
                 if arg in params:
                     _params[arg] = params[arg]
             val = val(a, b, **_params)
@@ -181,7+181,7 @@
         ham = 0
         for vector in tb_model.keys():
             ham += tb_model[vector] * np.exp(
-                1j * np.dot(k, np.array(vector, dtype=float))
+                -1j * np.dot(k, np.array(vector, dtype=float))
             )
         return ham