Add dtype = complex to UniaxialAnistropyOperator()

src/tetrax/core/operators.py

@@ -140,6 +140,7 @@ class UniAxialAnisotropyOperator(LinearOperator):
 
         self.sparse_mat = self.make_sparse_mat()
         self.shape = self.sparse_mat.shape
+        self.dtype = np.complex128
 
 
     def make_sparse_mat(self):