def test_apply_CZ(self):
# Classical CNOT
z0x0 = StabilizerState([[0, 0, 1, 0], [0, 1, 0, 0]])
z1x1 = StabilizerState([[0, 0, 1, 0, 1], [0, 1, 0, 0, 1]])
z0x0.apply_X(0)
z0x0.apply_CZ(0, 1)
z0x0.put_in_standard_form()
self.assertTrue(z0x0 == z1x1)
# EPR pair
z0z0 = StabilizerState([[0, 0, 1, 0], [0, 0, 0, 1]])
epr = StabilizerState([[1, 1, 0, 0], [0, 0, 1, 1]])
z0z0.apply_H(0)
# Effective CNOT
z0z0.apply_H(1)
z0z0.apply_CZ(0, 1)
z0z0.apply_H(1)
self.assertTrue(z0z0 == epr)
# Graph state
z0z0 = StabilizerState([[0, 0, 1, 0], [0, 0, 0, 1]])
graph_state = StabilizerState([[1, 0, 0, 1], [0, 1, 1, 0]])
z0z0.apply_H(0)
z0z0.apply_H(1)
# Effective CPHASE
z0z0.apply_CZ(0, 1)
self.assertTrue(z0z0 == graph_state)
def test_gaussian_elimination(self):
S = StabilizerState(["XZZ", "YIX", "IXX"])
S.put_in_standard_form()
self.assertTrue(
np.array_equal(
S.to_array(),
StabilizerState(["+1XZZ", "-1ZYZ", "-1ZZY"]).to_array()))
def test_standard_form(self):
tests = [ # stabilizers
["ZI", "IZ"],
["ZZ", "XX"],
["ZX", "XZ"],
["XXX", "ZZI", "IZZ"],
["XIII", "IXII", "IIXI", "IIIX"],
["XZII", "ZXZI", "IZXZ", "IIZX"], # line graph
["XZIZ", "ZXZI", "IZXZ", "ZIZX"], # cycle graph
["XZZZ", "ZXZZ", "ZZXZ", "ZZZX"], # complete graph
["XZZZ", "ZXII", "ZIXI", "ZIIX"], # star graph
]
for stabilizers in tests:
with self.subTest(stabilizers=stabilizers):
state = StabilizerState(stabilizers)
state.put_in_standard_form()
# Check that there are no X or Y in the first column except the first row
for row in state._group[1:, :]:
self.assertFalse(row[0])