QCoCircuits

qce_circuit is a Python package designed for the visualization of quantum circuits, with a particular focus on error correction circuits and device layouts.

Repository Structure

The package is organized into four main sections:

1. Quantum Circuit Construction: A declarative language for building quantum circuits, similar in style to popular packages like Qiskit and Quantify.
2. Device Layout Framework: A framework to describe arbitrary device layouts, with specific utilities for surface-code devices.
3. Visualization Framework: A powerful tool that translates the quantum circuit language into high-quality Matplotlib visualizations using draw-component factories and customizable style settings.
4. Addon Functionality: Includes supplementary features like circuit translation to Stim and OpenQL.

Examples

Here are a couple of examples to get you started.

Simple Circuit

This example demonstrates the basic functionality of the package, including the addition of gates, the use of RelationLinks to define the timing of operations, and the plotting of the final circuit.

from qce_circuit import (
    DeclarativeCircuit,
    FixedDurationStrategy,
    Ry90,
    Rym90,
    CPhase,
    Wait,
    DispersiveMeasure,
    Rx180,
    Barrier,
    Identity,
    RelationLink,
    RelationType,
    InitialStateEnum,
    plot_circuit,
)
from qce_circuit.structure.circuit_operations import (
    VirtualColorOverwrite,
)

# Circuit construction
circuit = DeclarativeCircuit()
circuit.add(Barrier([0, 1, 2]))
circuit.add(Ry90(0))
circuit.add(Ry90(1))
circuit.add(Ry90(2))
circuit.add(CPhase(2, 0))
circuit.add(CPhase(2, 1))
relation = RelationLink(circuit.get_last_entry(), RelationType.FOLLOWED_BY)
circuit.add(Rym90(0, relation=relation))
circuit.add(VirtualColorOverwrite(Rym90(1, relation=relation), color_overwrite="C1"))
circuit.add(Rym90(2, relation=relation))

relation = RelationLink(circuit.get_last_entry(), RelationType.FOLLOWED_BY)
# Ancilla measurement
for ancilla_index in [2]:
    circuit.add(DispersiveMeasure(
        ancilla_index,
        acquisition_strategy=circuit.get_acquisition_strategy(),
        acquisition_tag='parity',
        relation=relation,
    ))
dynamical_decoupling_wait = FixedDurationStrategy(duration=0.5)
for data_index in [0, 1]:
    circuit.add(Wait(data_index, duration_strategy=dynamical_decoupling_wait, relation=relation))
    circuit.add(Rx180(data_index))
    circuit.add(Wait(data_index, duration_strategy=dynamical_decoupling_wait))
relation = RelationLink(circuit.get_last_entry(), RelationType.FOLLOWED_BY)

circuit.add(Ry90(0, relation=relation))
circuit.add(Ry90(1, relation=relation))
circuit.add(Ry90(2, relation=relation))
circuit.add(CPhase(2, 0))
circuit.add(CPhase(2, 1))
relation = RelationLink(circuit.get_last_entry(), RelationType.FOLLOWED_BY)
circuit.add(Rym90(0, relation=relation))
circuit.add(Rym90(1, relation=relation))
circuit.add(Rym90(2, relation=relation))

circuit.add(Barrier([0, 1, 2]))
circuit.add(Identity(0))
circuit.add(Identity(1))
circuit.add(Barrier([0, 1, 2]))

# Data measurement
for qubit_index in [0, 1, 2]:
    circuit.add(DispersiveMeasure(
        qubit_index,
        acquisition_strategy=circuit.get_acquisition_strategy(),
        acquisition_tag='final',
    ))

# Define qubit mapping and initial states
channel_map = {
    i: name
    for i, name in enumerate(['D6', 'D3', 'Z2'])
}
circuit.set_qubit_initial_state(0, InitialStateEnum.ZERO)
circuit.set_qubit_initial_state(1, InitialStateEnum.ZERO)
circuit.set_qubit_initial_state(2, InitialStateEnum.ZERO)

# Plot the circuit
figsize_setting = (9, 3)
fig, ax = plot_circuit(
    circuit,
    channel_map=channel_map,
    figsize=figsize_setting,
)

Repetition Code

This example showcases a more advanced feature, using the RepetitionCodeDescription factory to construct a repetition code circuit. This is particularly useful for visualizing error correction circuits.

from qce_circuit import (
    DeclarativeCircuit,
    plot_circuit,
)
from qce_circuit.library.repetition_code.circuit_constructors import (
    RepetitionCodeDescription,
    construct_repetition_code_circuit_simplified,
)
from qce_circuit.library.repetition_code.repetition_code_connectivity import (
    Repetition9Round6Code,
    QubitIDObj,
)
from qce_circuit.visualization.visualize_layout.display_connectivity import (
    plot_stabilizer_specific_gate_sequences,
)


# Define the circuit description from connectivity
circuit_description = RepetitionCodeDescription.from_connectivity(
    involved_qubit_ids=[
        QubitIDObj('D1'), QubitIDObj('X1'), QubitIDObj('D2'),
        QubitIDObj('X2'), QubitIDObj('D3'), QubitIDObj('Z2'),
        QubitIDObj('D6'), QubitIDObj('Z4'), QubitIDObj('D5'),
        QubitIDObj('Z1'), QubitIDObj('D4'), QubitIDObj('Z3'),
        QubitIDObj('D7'), QubitIDObj('X3'), QubitIDObj('D8'),
        QubitIDObj('X4'), QubitIDObj('D9'),
    ],
    connectivity=Repetition9Round6Code()
)

# Construct the circuit
channel_order, channel_map = circuit_description.get_channel_order_and_mapping()
root_circuit: DeclarativeCircuit = construct_repetition_code_circuit_simplified(
    qec_cycles='N',
    description=circuit_description,
)

# Plot the circuit and stabilizer sequences
plot_stabilizer_specific_gate_sequences(Repetition9Round6Code())
plot_circuit(circuit=root_circuit, channel_order=channel_order, channel_map=channel_map, figsize=(10, 10))

Additional Examples