def test_channel_angle() -> None:
chan0 = qf.X(0).aschannel()
chan1 = qf.Y(0).aschannel()
qf.channel_angle(chan0, chan1)
assert not qf.channels_close(chan0, chan1)
assert qf.channels_close(chan0, chan0)
def test_chan_permute():
chan0 = qf.CNOT(0, 1).aschannel()
chan1 = qf.CNOT(1, 0).aschannel()
assert not qf.channels_close(chan0, chan1)
chan2 = chan1.permute([0, 1])
assert chan2.qubits == (0, 1)
assert qf.channels_close(chan1, chan2)
chan3 = chan1.relabel([0, 1])
assert qf.channels_close(chan0, chan3)
def test_channel_adjoint():
kraus0 = qf.Damping(0.1, 0)
chan0 = kraus0.aschannel()
chan1 = chan0.H.H
assert qf.channels_close(chan0, chan1)
chan2 = kraus0.H.aschannel()
assert qf.channels_close(chan2, chan0.H)
# 2 qubit hermitian channel
chan3 = qf.CZ(0, 1).aschannel()
chan4 = chan3.H
assert qf.channels_close(chan3, chan4)
def test_chan_permute() -> None:
chan0 = qf.CNot(0, 1).aschannel()
chan1 = qf.CNot(1, 0).aschannel()
assert not qf.channels_close(chan0, chan1)
chan2 = chan1.permute([0, 1])
assert chan2.qubits == (0, 1)
assert qf.channels_close(chan1, chan2)
chan3 = chan1.on(0, 1)
print(chan0.qubits, chan3.qubits)
assert qf.channels_close(chan0, chan3)
def _roundtrip(kraus):
assert qf.kraus_iscomplete(kraus)
chan0 = kraus.aschannel()
kraus1 = qf.channel_to_kraus(chan0)
assert qf.kraus_iscomplete(kraus1)
chan1 = kraus1.aschannel()
assert qf.channels_close(chan0, chan1)
def test_multiswapgate() -> None:
# Should be same as a swap.
perm0 = qf.MultiSwapGate([0, 1], [1, 0])
gate0 = qf.Swap(0, 1)
assert qf.gates_close(perm0.asgate(), gate0)
assert qf.gates_close(perm0.asgate(), perm0.H.asgate())
perm1 = qf.MultiSwapGate.from_gates(qf.Circuit([gate0]))
assert qf.gates_close(perm0.asgate(), perm1.asgate())
perm2 = qf.MultiSwapGate.from_gates(qf.Circuit([perm1]))
assert qf.gates_close(perm0, perm2)
with pytest.raises(ValueError):
qf.MultiSwapGate.from_gates(qf.Circuit(qf.CNot(0, 1)))
N = 8
qubits_in = list(range(N))
qubits_out = np.random.permutation(qubits_in)
permN = qf.MultiSwapGate(qubits_in, qubits_out)
assert qf.gates_close(perm0.asgate(), perm1.asgate())
iden = qf.Circuit([permN, permN.H])
assert qf.almost_identity(iden.asgate())
assert qf.circuits_close(iden, qf.Circuit([qf.IdentityGate(qubits_in)]))
swaps = qf.Circuit(permN.decompose())
# Add identity so we don't lose qubits
swaps += qf.IdentityGate(permN.qubits_in)
permN2 = qf.MultiSwapGate.from_gates(swaps)
assert qf.circuits_close(swaps, qf.Circuit([permN]))
assert qf.circuits_close(swaps, qf.Circuit([permN2]))
assert qf.circuits_close(qf.Circuit([permN]), qf.Circuit([permN2]))
with pytest.raises(ValueError):
_ = qf.MultiSwapGate([0, 1], [1, 2])
# Channels
assert qf.channels_close(perm0.aschannel(), gate0.aschannel())
rho0 = qf.random_state([0, 1, 3]).asdensity()
rho1 = perm0.evolve(rho0)
rho2 = gate0.aschannel().evolve(rho0)
assert qf.densities_close(rho1, rho2)
def test_partial_trace():
data = [1] * (2**16)
r8 = qf.QubitVector(data, range(2))
r4 = qf.QubitVector(data, range(4))
r2 = qf.QubitVector(data, range(8))
tr2 = r2.partial_trace([1])
assert tr2.qubits == (0, 2, 3, 4, 5, 6, 7)
assert tr2.rank == 2
tr2 = r2.partial_trace([2, 3])
assert tr2.qubits == (0, 1, 4, 5, 6, 7)
assert tr2.rank == 2
tr4 = r4.partial_trace([0])
assert tr4.qubits == (1, 2, 3)
assert tr4.rank == 4
tr8 = r8.partial_trace([1])
assert tr8.qubits == (0, )
assert tr8.rank == 8
with pytest.raises(ValueError):
r2.partial_trace(range(8))
chan012 = qf.identity_gate(3).aschannel()
assert np.isclose(qf.asarray(chan012.trace()), 64) # 2**(2**3)
chan02 = chan012.partial_trace([1])
assert np.isclose(qf.asarray(chan02.trace()), 32) # TODO: Checkme
chan2 = chan012.partial_trace([0, 1])
assert np.isclose(qf.asarray(chan2.trace()), 16) # TODO: checkme
# partial traced channels should be identities still, upto normalization
assert qf.channels_close(chan2, qf.I(2).aschannel())
# TODO: Channel.normalize()
with pytest.raises(ValueError):
qf.zero_state(4).vec.partial_trace([1, 2])
def test_channle_choi() -> None:
chan0 = qf.Damping(0.1, 0).aschannel()
choi = chan0.choi()
chan1 = qf.Channel.from_choi(choi, [0])
assert qf.channels_close(chan0, chan1)