From Circuit to Executable Pattern

This example transpiles an MBQC-native circuit into GraphQOMB’s compiler IRs, then lowers them to an executable pattern and validates it by simulation.

import numpy as np

from graphqomb.circuit import MBQCCircuit, circuit2graph
from graphqomb.pattern import print_pattern
from graphqomb.qompiler import qompile
from graphqomb.simulator import (
    CircuitSimulator,
    PatternSimulator,
    SimulatorBackend,
)

generate circuit

circuit = MBQCCircuit(3)
circuit.j(0, 0.5 * np.pi)
circuit.cz(0, 1)
circuit.cz(0, 2)
circuit.j(1, 0.75 * np.pi)
circuit.j(2, 0.25 * np.pi)
circuit.cz(0, 2)
circuit.cz(1, 2)

Convert the circuit into GraphQOMB’s compiler IRs.

graphstate, xflow, scheduler = circuit2graph(circuit)
print("graph nodes:", len(graphstate.nodes))
print("graph edges:", len(graphstate.edges))
print("feedforward entries:", len(xflow))
print("scheduled slices:", scheduler.num_slices())

# Lower the IRs into an executable pattern using the derived schedule.
pattern = qompile(graphstate, xflow, scheduler=scheduler)
print("pattern depth:", pattern.depth)
print("pattern max space:", pattern.max_space)
print("pattern active volume:", pattern.active_volume)
print_pattern(pattern)

graph nodes: 6
graph edges: 7
feedforward entries: 3
scheduled slices: 3
pattern depth: 3
pattern max space: 5
pattern active volume: 15
N: node=3
E: nodes=(2, 3)
E: nodes=(0, 3)
E: nodes=(1, 3)
TICK
N: node=4
N: node=5
E: nodes=(1, 4)
E: nodes=(4, 5)
E: nodes=(2, 5)
E: nodes=(3, 5)
M: node=0, plane=Plane.XY, angle=-1.5707963267948966
TICK
M: node=1, plane=Plane.XY, angle=-2.356194490192345
M: node=2, plane=Plane.XY, angle=-0.7853981633974483
TICK
X: node=3
Z: node=3
X: node=4
Z: node=4
X: node=5
Z: node=5
0 more commands truncated. Change lim argument of print_pattern() to show more

simulate the pattern

simulator = PatternSimulator(pattern, SimulatorBackend.StateVector)
simulator.simulate()
state = simulator.state
statevec = state.state()

# check by comparing the circuit simulator
circ_simulator = CircuitSimulator(circuit, SimulatorBackend.StateVector)
circ_simulator.simulate()
circ_state = circ_simulator.state.state()
inner_product = np.vdot(statevec, circ_state)
print("inner product:", np.abs(inner_product))  # should be 1

inner product: 0.9999999999999994