def test_EntropyConcurrence():
"Entropy: Concurrence"
# check concurrence = 1 for maximal entangled (Bell) state
bell = ket2dm(
(tensor(basis(2), basis(2)) + tensor(basis(2, 1), basis(2, 1))).unit())
assert_equal(abs(concurrence(bell) - 1.0) < 1e-15, True)
# check all concurrence values >=0
rhos = [rand_dm(4, dims=[[2, 2], [2, 2]]) for k in range(10)]
for k in rhos:
assert_equal(concurrence(k) >= 0, True)
def test_EntropyConcurrence():
"Concurrence"
# check concurrence = 1 for maximal entangled (Bell) state
bell = ket2dm(
(tensor(basis(2), basis(2)) + tensor(basis(2, 1), basis(2, 1))).unit())
assert_equal(abs(concurrence(bell) - 1.0) < 1e-15, True)
# check all concurrence values >=0
rhos = [rand_dm(4, dims=[[2, 2], [2, 2]]) for k in range(10)]
for k in rhos:
assert_equal(concurrence(k) >= 0, True)
def test_nonzero(self):
dm = qutip.rand_dm(4, dims=[[2, 2], [2, 2]])
assert qutip.concurrence(dm) >= 0
def test_maximally_entangled(self, dm):
assert abs(qutip.concurrence(dm) - 1) < 1e-12