def test_rotations_pulse(self):
q0 = Transmon("q0", levels=2)
q1 = Transmon("q1", levels=3, kerr=-200e-3)
q0.gaussian_pulse.sigma = 40
q1.gaussian_pulse.sigma = 40
system = System("system", modes=[q0, q1])
init_state = system.fock()
for qubit in [q0, q1]:
for _ in range(1):
_ = tune_rabi(system,
init_state=init_state,
mode_name=qubit.name,
verify=False)
angles = np.linspace(-np.pi, np.pi, 5)
for angle in angles:
for qubit in [q0, q1]:
seq = get_sequence(system)
qubit.rotate_x(angle)
unitary = qubit.rotate_x(angle, unitary=True)
result = seq.run(init_state)
fidelity = qutip.fidelity(result.states[-1],
unitary * init_state)**2
self.assertGreater(fidelity, 1 - 1e-2)
seq = get_sequence(system)
qubit.rotate_y(angle)
unitary = qubit.rotate_y(angle, unitary=True)
result = seq.run(init_state)
fidelity = qutip.fidelity(result.states[-1],
unitary * init_state)**2
self.assertGreater(fidelity, 1 - 1e-2)
def setUpClass(cls):
qubit = Transmon("qubit", levels=2)
cavity = Cavity("cavity", levels=6)
system = System("system", modes=[qubit, cavity])
system.set_cross_kerr(qubit, cavity, -2e-3)
with system.use_modes([qubit]):
_ = tune_rabi(system, init_state=qubit.fock(0), verify=False)
cls.system = system
def setUpClass(cls):
q0 = Transmon("q0", levels=2)
q1 = Transmon("q1", levels=2)
system = System("system", modes=[q0, q1])
for qubit in [q0, q1]:
init_state = system.fock()
for _ in range(1):
_ = tune_rabi(
system, init_state=init_state, mode_name=qubit.name, verify=False
)
cls.system = system
def test_rabi_two_levels(self):
qubit = Transmon("qubit", levels=2)
system = System("system", modes=[qubit])
for _ in range(2):
_, old_amp, new_amp = tune_rabi(system, qubit.fock(0))
self.assertLess(abs(old_amp - new_amp), 1e-7)
init = qubit.fock(0)
seq = get_sequence(system)
qubit.rotate_x(np.pi)
result = seq.run(init)
target = qubit.Rx(np.pi) * init
fidelity = qutip.fidelity(result.states[-1], target)**2
self.assertLess(abs(1 - fidelity), 1e-10)
def setUpClass(cls):
n = 5
qubits = [
Transmon(
f"q{i}",
# levels=2,
# # comment out the above line and uncomment the
# # below line to use 3-level transmons with
# # various anharmonicities
levels=3,
kerr=-100e-3 * (i + 1),
)
for i in reversed(range(n))
]
qreg = System("qreg", modes=qubits)
# Tune pi pulses for all qubits
for i, qubit in enumerate(qubits):
# Use different sigmas so that pulses can be visually distinguished
qubit.gaussian_pulse.set(sigma=(10 + 2 * i), chop=4)
with qreg.use_modes([qubit]):
init_state = qubit.fock(0)
e_ops = [qubit.fock_dm(1)]
_ = tune_rabi(
qreg,
init_state,
e_ops=e_ops,
mode_name=qubit.name,
plot=False,
verify=False,
)
# # Below line is unnecessary if the qubits
# # only have two levels
_ = tune_drag(
qreg, init_state, e_ops=e_ops, mode_name=qubit.name, plot=False
)
def bell_state(qreg):
zeros = [0] * len(qreg.active_modes)
ones = [1] * len(qreg.active_modes)
return (qreg.logical_basis(*zeros) + qreg.logical_basis(*ones)).unit()
cls.ideal_state = bell_state(qreg)
cls.qreg = qreg
def test_drag(self):
qubit = Transmon("qubit", levels=3, kerr=-200e-3)
qubit.gaussian_pulse.sigma = 10
system = System("system", modes=[qubit])
for _ in range(3):
_, old_amp, new_amp = tune_rabi(system,
qubit.fock(0),
plot=False,
verify=False)
self.assertLess(abs(old_amp - new_amp), 1e-7)
_, old_drag, new_drag = tune_drag(system, qubit.fock(0), update=True)
self.assertNotAlmostEqual(new_drag, 0)
init = qubit.fock(0)
seq = get_sequence(system)
qubit.rotate_x(np.pi)
result = seq.run(init)
target = qubit.Rx(np.pi) * init
fidelity = qutip.fidelity(result.states[-1], target)**2
self.assertLess(abs(1 - fidelity), 1e-5)