def test_compose(self):
"""Test compose method."""
# Random input test state
rho = self.rand_rho(2)
# UnitaryChannel evolution
chan1 = PTM(self.ptmX)
chan2 = PTM(self.ptmY)
chan = chan1.compose(chan2)
targ = PTM(self.ptmZ)._evolve(rho)
self.assertAllClose(chan._evolve(rho), targ)
# 50% depolarizing channel
chan1 = PTM(self.depol_ptm(0.5))
chan = chan1.compose(chan1)
targ = PTM(self.depol_ptm(0.75))._evolve(rho)
self.assertAllClose(chan._evolve(rho), targ)
# Compose random
ptm1 = self.rand_matrix(4, 4, real=True)
ptm2 = self.rand_matrix(4, 4, real=True)
chan1 = PTM(ptm1, input_dims=2, output_dims=2)
chan2 = PTM(ptm2, input_dims=2, output_dims=2)
targ = chan2._evolve(chan1._evolve(rho))
chan = chan1.compose(chan2)
self.assertEqual(chan.dim, (2, 2))
self.assertAllClose(chan._evolve(rho), targ)
chan = chan1 @ chan2
self.assertEqual(chan.dim, (2, 2))
self.assertAllClose(chan._evolve(rho), targ)
def test_compose_front(self):
"""Test front compose method."""
# Random input test state
rho = self.rand_rho(2)
# UnitaryChannel evolution
chan1 = PTM(self.ptmX)
chan2 = PTM(self.ptmY)
chan = chan2.compose(chan1, front=True)
targ = PTM(self.ptmZ)._evolve(rho)
self.assertAllClose(chan._evolve(rho), targ)
# Compose random
ptm1 = self.rand_matrix(4, 4, real=True)
ptm2 = self.rand_matrix(4, 4, real=True)
chan1 = PTM(ptm1, input_dims=2, output_dims=2)
chan2 = PTM(ptm2, input_dims=2, output_dims=2)
targ = chan2._evolve(chan1._evolve(rho))
chan = chan2.compose(chan1, front=True)
self.assertEqual(chan.dim, (2, 2))
self.assertAllClose(chan._evolve(rho), targ)
def test_evolve(self):
"""Test evolve method."""
input_psi = [0, 1]
input_rho = [[0, 0], [0, 1]]
# Identity channel
chan = PTM(self.ptmI)
target_rho = np.array([[0, 0], [0, 1]])
self.assertAllClose(chan._evolve(input_psi), target_rho)
self.assertAllClose(chan._evolve(np.array(input_psi)), target_rho)
self.assertAllClose(chan._evolve(input_rho), target_rho)
self.assertAllClose(chan._evolve(np.array(input_rho)), target_rho)
# Hadamard channel
chan = PTM(self.ptmH)
target_rho = np.array([[1, -1], [-1, 1]]) / 2
self.assertAllClose(chan._evolve(input_psi), target_rho)
self.assertAllClose(chan._evolve(np.array(input_psi)), target_rho)
self.assertAllClose(chan._evolve(input_rho), target_rho)
self.assertAllClose(chan._evolve(np.array(input_rho)), target_rho)
# Completely depolarizing channel
chan = PTM(self.depol_ptm(1))
target_rho = np.eye(2) / 2
self.assertAllClose(chan._evolve(input_psi), target_rho)
self.assertAllClose(chan._evolve(np.array(input_psi)), target_rho)
self.assertAllClose(chan._evolve(input_rho), target_rho)
self.assertAllClose(chan._evolve(np.array(input_rho)), target_rho)
