def test_majorana_form(self):
"""Test getting the Majorana form."""
majorana_matrix, majorana_constant = self.quad_ham_npc.majorana_form()
# Convert the Majorana form to a FermionOperator
majorana_op = FermionOperator((), majorana_constant)
normalization = 1. / numpy.sqrt(2.)
for i in range(2 * self.n_qubits):
if i < self.n_qubits:
left_op = majorana_operator((i, 0), normalization)
else:
left_op = majorana_operator((i - self.n_qubits, 1),
normalization)
for j in range(2 * self.n_qubits):
if j < self.n_qubits:
right_op = majorana_operator(
(j, 0), majorana_matrix[i, j] * normalization)
else:
right_op = majorana_operator(
(j - self.n_qubits, 1),
majorana_matrix[i, j] * normalization)
majorana_op += .5j * left_op * right_op
# Get FermionOperator for original Hamiltonian
fermion_operator = normal_ordered(
get_fermion_operator(self.quad_ham_npc))
self.assertTrue(normal_ordered(majorana_op) == fermion_operator)
def test_bad_term(self):
with self.assertRaises(ValueError):
majorana_operator((2, 2))
with self.assertRaises(ValueError):
majorana_operator('a')
with self.assertRaises(ValueError):
majorana_operator(2)
def test_init(self):
# Test 'c' operator
op1 = majorana_operator((2, 0))
op2 = majorana_operator('c2')
op3 = majorana_operator(u'c2')
correct = FermionOperator('2^') + FermionOperator('2')
self.assertEqual(op1, op2)
self.assertEqual(op1, op3)
self.assertEqual(op1, correct)
# Test 'd' operator
op1 = majorana_operator((3, 1))
op2 = majorana_operator('d3')
correct = FermionOperator('3^', 1.j) - FermionOperator('3', 1.j)
self.assertEqual(op1, op2)
self.assertEqual(op1, correct)
with self.assertRaises(ValueError):
_ = majorana_operator('A2')
def test_bad_coefficient(self):
with self.assertRaises(ValueError):
majorana_operator((1, 1), 'a')
def test_none_term(self):
majorana_operator()
self.assertEqual(majorana_operator(), FermionOperator())
def stabilizer(i, j):
"""Stabilizer operators which act on the auxiliary space.
In the original paper, these are referred to as P_{ij}."""
c_i = majorana_operator((i, 0))
d_j = majorana_operator((j, 1))
return 1.j * c_i * d_j
