import discretisedfield as df
import numpy as np
p = [1, 1, 0, 0]
mu = 0.5 * np.array([[p[0] + p[1], p[2] - 1j * p[3]], [p[2] + 1j * p[3], p[0] - p[1]]])
mu
array([[1.+0.j, 0.+0.j],
[0.+0.j, 0.+0.j]])
np.dot(mu, mu)
array([[1.+0.j, 0.+0.j],
[0.+0.j, 0.+0.j]])