cQASM converter

As usual, we start by importing the needed libraries. Note that this notebook requires the installation of cQASM (which can be easily done with pip install libqasm). This repository can also be installed with the command: pip install .[CQASM-bridge] to automatically install cQASM.

from perceval_interop import CQASMConverter
from perceval import pdisplay

Then we write our cQASM program.

cqasm_program = """
version 3
qubit[2] q
H q[0]
CNOT q[0], q[1]
"""

We convert it with the Perceval CQASMConverter.

perceval_processor = CQASMConverter().convert(cqasm_program, use_postselection=False)

The output probabilities can now be computed using Perceval.

r = perceval_processor.probs()['results']
print('results:', r)
pdisplay(perceval_processor)

results: {
        |1,0,1,0>: 0.5000000000000002
        |0,1,0,1>: 0.4999999999999999
}

The 1.0 version of cQASM is also supported, as shown in the example below.

# version 1.0
cqasm_program = f"""
version 1.0

# a basic cQASM example
qubits 2

.prepare
prep_z q[0:1]

.entangle
H q[0]
CNOT q[0], q[1]

.measurement
measure_all
"""

perceval_processor = CQASMConverter().convert(cqasm_program, use_postselection=False)

r = perceval_processor.probs()['results']
print('results:', r)
pdisplay(perceval_processor)

results: {
        |1,0,1,0>: 0.5000000000000002
        |0,1,0,1>: 0.4999999999999999
}

The cQASM program can also be retrieved from a file by using CQASMConverter().convert(path_to_cqasm_program).