def test_tensor(self):
"""Test tensor method."""
rho0, rho1 = np.diag([1, 0]), np.diag([0, 1])
rho_init = DensityMatrix(np.kron(rho0, rho0))
chan1 = Stinespring(self.UI)
chan2 = Stinespring(self.UX)
# X \otimes I
chan = chan2.tensor(chan1)
rho_targ = DensityMatrix(np.kron(rho1, rho0))
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
# I \otimes X
chan = chan1.tensor(chan2)
rho_targ = DensityMatrix(np.kron(rho0, rho1))
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
# Completely depolarizing
chan_dep = Stinespring(self.depol_stine(1))
chan = chan_dep.tensor(chan_dep)
rho_targ = DensityMatrix(np.diag([1, 1, 1, 1]) / 4)
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
def test_sub_qargs(self):
"""Test sub method with qargs."""
rho = DensityMatrix(self.rand_rho(8))
stine = self.rand_matrix(32, 8)
stine0 = self.rand_matrix(8, 2)
op = Stinespring(stine)
op0 = Stinespring(stine0)
eye = Stinespring(self.UI)
with self.subTest(msg="qargs=[0]"):
value = op - op0([0])
target = op - eye.tensor(eye).tensor(op0)
self.assertEqual(rho & value, rho & target)
with self.subTest(msg="qargs=[1]"):
value = op - op0([1])
target = op - eye.tensor(op0).tensor(eye)
self.assertEqual(rho & value, rho & target)
with self.subTest(msg="qargs=[2]"):
value = op - op0([2])
target = op - op0.tensor(eye).tensor(eye)
self.assertEqual(rho & value, rho & target)
def test_add_qargs(self):
"""Test add method with qargs."""
rho = DensityMatrix(self.rand_rho(8))
stine = self.rand_matrix(32, 8)
stine0 = self.rand_matrix(8, 2)
op = Stinespring(stine)
op0 = Stinespring(stine0)
eye = Stinespring(self.UI)
with self.subTest(msg='qargs=[0]'):
value = op + op0([0])
target = op + eye.tensor(eye).tensor(op0)
self.assertEqual(rho @ value, rho @ target)
with self.subTest(msg='qargs=[1]'):
value = op + op0([1])
target = op + eye.tensor(op0).tensor(eye)
self.assertEqual(rho @ value, rho @ target)
with self.subTest(msg='qargs=[2]'):
value = op + op0([2])
target = op + op0.tensor(eye).tensor(eye)
self.assertEqual(rho @ value, rho @ target)