# Pulse waveform for 2-qubit circuit

I'm trying to reproduce the Bell-state pulse display as shown in this tutorial. The code is very short:

bell = QuantumCircuit(2, 2)
bell.h(0)
bell.cx(0,1)
qc = transpile(bell,backend)
sched_circ = schedule(qc,backend)
sched_circ.draw()


but if I use the backend ibmq_armonk there are not enough qubits and, for ibmq_qasm_simulator, Qiskit-pulse is not supported. Is there a way to get it working? I do not need to run the waveforms on a device - I just want to analyze them.

P.S. If anyone has a compact IO protocol writing/reading scheduler pulses for multi-qubit Qiskit circuits in HD5 format I'd be interested to collaborate.

Follow up: After I upgraded my qiskit to ver 0.25.3 the backend=FakeOpenPulse2Q() works exactly as suggested below. Thanks for the help. Jan

## 1 Answer

You can use fake pulse backend to do this.

from qiskit.circuit import QuantumCircuit
import matplotlib.pyplot as plt
from qiskit.test.mock import FakeOpenPulse2Q
backend = FakeOpenPulse2Q()
from qiskit import transpile, schedule
bell = QuantumCircuit(2, 2)
bell.h(0)
bell.cx(0,1)
qc = transpile(bell,backend)
pulse_schedule = schedule(qc, backend)

fig, ax = plt.subplots(figsize=(14, 10))
pulse_schedule.draw('IQXDebugging', axis = ax, show_waveform_info = True)



You will get something like below:

• Brilliant! Thanks a lot. A minor follow-up. I run a stand-alone python script (no Jupyter). Is there a way to control the Matplotlib 'ax' - the default sched_circ.draw() takes all the screen. Idealy, I'd like sth like this: '''import matplotlib.pyplot as plt plt.figure(figsize=(8, 6)) ax = plt.subplot(1, 1, 1) sched_circ.draw(plot_range=[0, 400],ax=ax) plt.show() ''' but 'ax' or 'axis' is not on the list of sched_circ.draw.__code__.co_varnames May 7 at 15:44
• I edited the answer to include the change of fig size. :) Also look here for more details: qiskit.org/documentation/stubs/… May 7 at 17:03
• thank you for the advice - all work for me now as I wanted. (My Qiskit vers was too old - I updated it). If anyone is interested in collaborating on storing multi-qubit circuit waveforms as HD5 please contact me. May 7 at 17:36