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 = Choi(self.choiI)
chan2 = Choi(self.choiX)
# X \otimes I
rho_targ = DensityMatrix(np.kron(rho1, rho0))
chan = chan2.tensor(chan1)
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
chan = chan2 ^ chan1
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
# I \otimes X
rho_targ = DensityMatrix(np.kron(rho0, rho1))
chan = chan1.tensor(chan2)
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
chan = chan1 ^ chan2
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
# Completely depolarizing
rho_targ = DensityMatrix(np.diag([1, 1, 1, 1]) / 4)
chan_dep = Choi(self.depol_choi(1))
chan = chan_dep.tensor(chan_dep)
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
chan = chan_dep ^ chan_dep
self.assertEqual(chan.dim, (4, 4))
self.assertEqual(rho_init.evolve(chan), rho_targ)
def test_sub_qargs(self):
"""Test subtract method with qargs."""
mat = self.rand_matrix(8**2, 8**2)
mat0 = self.rand_matrix(4, 4)
mat1 = self.rand_matrix(4, 4)
op = Choi(mat)
op0 = Choi(mat0)
op1 = Choi(mat1)
op01 = op1.tensor(op0)
eye = Choi(self.choiI)
with self.subTest(msg="qargs=[0]"):
value = op - op0([0])
target = op - eye.tensor(eye).tensor(op0)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[1]"):
value = op - op0([1])
target = op - eye.tensor(op0).tensor(eye)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[2]"):
value = op - op0([2])
target = op - op0.tensor(eye).tensor(eye)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[0, 1]"):
value = op - op01([0, 1])
target = op - eye.tensor(op1).tensor(op0)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[1, 0]"):
value = op - op01([1, 0])
target = op - eye.tensor(op0).tensor(op1)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[0, 2]"):
value = op - op01([0, 2])
target = op - op1.tensor(eye).tensor(op0)
self.assertEqual(value, target)
with self.subTest(msg="qargs=[2, 0]"):
value = op - op01([2, 0])
target = op - op0.tensor(eye).tensor(op1)
self.assertEqual(value, target)
def test_tensor_inplace(self):
"""Test inplace tensor method."""
rho0, rho1 = np.diag([1, 0]), np.diag([0, 1])
rho_init = np.kron(rho0, rho0)
# X \otimes I
rho_targ = np.kron(rho1, rho0)
chan1 = Choi(self.choiI)
chan2 = Choi(self.choiX)
chan2.tensor(chan1, inplace=True)
self.assertEqual(chan2.dims, (4, 4))
self.assertAllClose(chan2._evolve(rho_init), rho_targ)
chan1 = Choi(self.choiI)
chan2 = Choi(self.choiX)
chan2 ^= chan1
self.assertEqual(chan2.dims, (4, 4))
self.assertAllClose(chan2._evolve(rho_init), rho_targ)
# I \otimes X
rho_targ = np.kron(rho0, rho1)
chan1 = Choi(self.choiI)
chan2 = Choi(self.choiX)
chan1.tensor(chan2, inplace=True)
self.assertEqual(chan1.dims, (4, 4))
self.assertAllClose(chan1._evolve(rho_init), rho_targ)
chan1 = Choi(self.choiI)
chan2 = Choi(self.choiX)
chan1 ^= chan2
self.assertEqual(chan1.dims, (4, 4))
self.assertAllClose(chan1._evolve(rho_init), rho_targ)
# Completely depolarizing
rho_targ = np.diag([1, 1, 1, 1]) / 4
chan = Choi(self.depol_choi(1))
chan.tensor(chan, inplace=True)
self.assertEqual(chan.dims, (4, 4))
self.assertAllClose(chan._evolve(rho_init), rho_targ)
chan = Choi(self.depol_choi(1))
chan ^= chan
self.assertEqual(chan.dims, (4, 4))
self.assertAllClose(chan._evolve(rho_init), rho_targ)