def test_use_modes(self):
qubit = Transmon("qubit", levels=3, kerr=-200e-3)
cavity = Cavity("cavity", levels=10, kerr=-10e-6)
system = System("system", modes=[qubit, cavity])
with system.use_modes([qubit]):
self.assertEqual(system.ground_state(), qubit.fock(0, full_space=False))
with system.use_modes([cavity]):
self.assertEqual(system.ground_state(), cavity.fock(0, full_space=False))
with system.use_modes([qubit, cavity]):
self.assertEqual(
system.ground_state(),
qutip.tensor(
qubit.fock(0, full_space=False), cavity.fock(0, full_space=False)
),
)
system.order_modes = False
with system.use_modes([cavity, qubit]):
self.assertEqual(
system.ground_state(),
qutip.tensor(
cavity.fock(0, full_space=False), qubit.fock(0, full_space=False)
),
)
def test_displacement(self):
cavity = Cavity("cavity", levels=12)
system = System("system", modes=[cavity])
for _ in range(3):
_, old_amp, new_amp = tune_displacement(system, cavity.fock(0))
self.assertLess(abs(old_amp - new_amp), 1e-7)
init = cavity.fock(0)
seq = get_sequence(system)
cavity.displace(1 + 2j)
result = seq.run(init)
target = cavity.D(1 + 2j) * init
fidelity = qutip.fidelity(result.states[-1], target)**2
self.assertLess(abs(1 - fidelity), 1e-7)