examples: more sensible factors of 2 in definition

examples/bulk_j_an.py

@@ -33,8 +33,8 @@ def get_solver(soc_alpha, eta, L=10, h=0.5, D=1.0, n=5):
     dx = sol.Lx / nx
     dy = sol.Ly / ny
 
-    Ax = 2 * soc_alpha * np.kron(S_0, S_y)
-    Ay = -2 * soc_alpha * np.kron(S_0, S_x)
+    Ax = soc_alpha * np.kron(S_0, S_y)
+    Ay = -soc_alpha * np.kron(S_0, S_x)
 
     sol.Ux[...] = expm(1j * dx * Ax)
     sol.Uy[...] = expm(1j * dy * Ay)
@@ -93,8 +93,8 @@ def j_anom(T, h, n=5, alpha_soc=0.01, perturbative=False):
         gm = (ww + 1j * h) / np.sqrt((ww + 1j * h) ** 2 + 1)
         fp = 1 / np.sqrt((ww - 1j * h) ** 2 + 1)
         fm = 1 / np.sqrt((ww + 1j * h) ** 2 + 1)
-        # XXX: check the 8*eta
-        Jy_an = (gp - gm) * (1 + gp * gm + fp * fm) * (-1j * alpha_soc**3) * (8 * eta)
+        # XXX: check factors of 2
+        Jy_an = (gp - gm) * (1 + gp * gm + fp * fm) * (-1j * alpha_soc**3) * eta
         Jantot += pi * aa * Jy_an
 
     return Jtot, Jantot