def test_purity_mixed_state(self):
state_1 = 0.5 * (projector(basis_state('0', 1)) +
projector(basis_state('1', 1)))
state_2 = (1 / 3.0) * (projector(basis_state('00', 2)) + projector(
basis_state('01', 2)) + projector(basis_state('10', 2)))
self.assertEqual(purity(state_1), 0.5)
self.assertEqual(purity(state_2), 1.0 / 3)
def test_purity_pure_matrix_state(self):
state_1 = (1/np.sqrt(2))*(basis_state('0', 1) + basis_state('1', 1))
state_1 = projector(state_1)
state_2 = (1/np.sqrt(3))*(basis_state('00', 2)
+ basis_state('01', 2) + basis_state('11', 2))
state_2 = projector(state_2)
state_3 = 0.5*(basis_state('000', 3) + basis_state('001', 3)
+ basis_state('010', 3) + basis_state('100', 3))
state_3 = projector(state_3)
self.assertAlmostEqual(purity(state_1), 1.0, places=10)
self.assertAlmostEqual(purity(state_2), 1.0, places=10)
self.assertEqual(purity(state_3), 1.0)
def test_projector(self):
"""TO BE REMOVED with qiskit.quantum_info.basis_state"""
state0 = np.array([1. + 0.j, 0. + 0.j])
with self.assertWarns(DeprecationWarning):
state1 = projector(np.array([0. + 0.j, 1. + 0.j]))
self.assertEqual(state_fidelity(state0, state0), 1.0)
self.assertEqual(state_fidelity(state1, state1), 1.0)
self.assertEqual(state_fidelity(state0, state1), 0.0)
def test_projector(self):
state0 = np.array([1. + 0.j, 0. + 0.j])
state1 = projector(np.array([0. + 0.j, 1. + 0.j]))
self.assertEqual(state_fidelity(state0, state0), 1.0)
self.assertEqual(state_fidelity(state1, state1), 1.0)
self.assertEqual(state_fidelity(state0, state1), 0.0)
