def _build_cr_schedule(
self,
backend: Backend,
flat_top_width: float,
sigma: float,
) -> pulse.ScheduleBlock:
"""GaussianSquared cross resonance pulse.
Args:
backend: The target backend.
flat_top_width: Total length of flat top part of the pulse in units of dt.
sigma: Sigma of Gaussian edges in units of dt.
Returns:
A schedule definition for the cross resonance pulse to measure.
"""
opt = self.experiment_options
# Compute valid integer duration
cr_duration = round_pulse_duration(backend=backend,
duration=flat_top_width +
2 * sigma * opt.risefall)
with pulse.build(backend, default_alignment="left",
name="cr") as cross_resonance:
# add cross resonance tone
pulse.play(
pulse.GaussianSquare(
duration=cr_duration,
amp=opt.amp,
sigma=sigma,
width=flat_top_width,
),
pulse.control_channels(*self.physical_qubits)[0],
)
# add cancellation tone
if not np.isclose(opt.amp_t, 0.0):
pulse.play(
pulse.GaussianSquare(
duration=cr_duration,
amp=opt.amp_t,
sigma=sigma,
width=flat_top_width,
),
pulse.drive_channel(self.physical_qubits[1]),
)
else:
pulse.delay(cr_duration,
pulse.drive_channel(self.physical_qubits[1]))
# place holder for empty drive channels. this is necessary due to known pulse gate bug.
pulse.delay(cr_duration,
pulse.drive_channel(self.physical_qubits[0]))
return cross_resonance
def test_control_channel(self):
"""Text context builder control channel."""
with pulse.build(self.backend):
self.assertEqual(pulse.control_channels(0, 1)[0],
pulse.ControlChannel(0))