Serialization

vqubit can save and load circuits as text, and export them to OpenQASM 2.0.

JSON

Every serializable value becomes a JSON object carrying a cirq_type field, and read_json rebuilds it.

import vqubit as vq

q0, q1 = vq.LineQubit.range(2)
circuit = vq.Circuit(vq.H(q0), vq.CNOT(q0, q1), vq.Rz(0.3)(q1))

text = vq.to_json(circuit)
recovered = vq.read_json(text)
print(recovered == circuit)   # True

There are compressed variants too:

data = vq.to_json_gzip(circuit)          # compressed bytes
assert vq.read_json_gzip(data) == circuit

You can ask for a value's type name and look a class up by it:

print(vq.json_cirq_type(vq.X))             # 'XPowGate'
print(vq.cirq_type_from_json('LineQubit')) # <class 'vqubit._qubits.LineQubit'>

OpenQASM 2.0

import vqubit as vq

q0, q1 = vq.LineQubit.range(2)
circuit = vq.Circuit(vq.H(q0), vq.CNOT(q0, q1), vq.measure(q0, q1, key="m"))
print(vq.qasm(circuit))

It produces:

// Generated by vqubit
OPENQASM 2.0;
include "qelib1.inc";
qreg q[2];
creg m_m[2];
h q[0];
cx q[0],q[1];
measure q[0] -> m_m[0];
measure q[1] -> m_m[1];

Gates without a native instruction (like the Fredkin gate) are expanded through their decomposition before being written.

Quirk

quirk_url renders a circuit as a link to the Quirk simulator, for the gates Quirk understands natively:

q0, q1 = vq.LineQubit.range(2)
circuit = vq.Circuit(vq.H(q0), vq.CNOT(q0, q1))
print(vq.quirk_url(circuit))   # https://algassert.com/quirk#circuit=...

The QasmArgs object carries the context (qubit names, precision and free arguments) that a gate's QASM writer receives.

Next steps

• Run your circuits on local devices.