SPDX-License-Identifier: AGPL-3.0-or-later

Commercial license available

© Concepts 1996–2026 Miroslav Šotek. All rights reserved.

© Code 2020–2026 Miroslav Šotek. All rights reserved.

ORCID: 0009-0009-3560-0851

Contact: www.anulum.li | protoscience@anulum.li

scpn-quantum-control — Hybrid Digital-Analog Execution

Hybrid Digital-Analog Execution

The hybrid compiler splits a validated Kuramoto-XY workload into two coherent execution blocks:

• an analog-native block for couplings that can be realised directly on a neutral-atom, circuit-QED, or continuous-variable platform;
• a digital residual block for the remaining couplings, compiled as a Trotter circuit.

Local detunings are assigned to the analog block. The digital residual uses zero local detunings so the same single-oscillator terms are not counted twice when a provider adapter executes the schedule.

Usage

import numpy as np

from scpn_quantum_control.hardware.hybrid_digital_analog import (
    compile_hybrid_digital_analog,
)

K_nm = np.array(
    [
        [0.0, 0.8, -0.4, 0.1],
        [0.8, 0.0, 0.3, 0.0],
        [-0.4, 0.3, 0.0, -0.2],
        [0.1, 0.0, -0.2, 0.0],
    ],
    dtype=np.float64,
)
omega = np.array([0.1, -0.2, 0.05, 0.3], dtype=np.float64)

program = compile_hybrid_digital_analog(
    K_nm,
    omega,
    platform="circuit_qed",
    duration=1.25,
    max_analog_couplers=2,
    trotter_steps=3,
)

print(program.n_analog_couplers, program.n_digital_couplers)
print(program.payload["schema"])

The same compiler is available through the public Kuramoto facade:

from scpn_quantum_control.kuramoto_core import (
    build_kuramoto_problem,
    compile_hybrid_program,
)

problem = build_kuramoto_problem(K_nm, omega, metadata={"case": "demo"})
program = compile_hybrid_program(
    problem,
    platform="neutral_atoms",
    duration=0.75,
    analog_threshold=0.35,
)

Coupling Split

The splitter treats the upper triangle of K_nm as the source of coupling terms. Couplings with abs(K_ij) <= zero_threshold are ignored. Eligible analog couplings are ranked by descending abs(K_ij) and then by (i, j) for deterministic tie-breaking. max_analog_couplers limits how many of those couplings are routed to analog execution.

analog_threshold can be used when a platform should only receive large native terms. Couplings below that threshold remain in the digital residual even when analog capacity is available.

The Rust extension exposes the same deterministic partitioner as scpn_quantum_engine.hybrid_coupling_partition. The Python implementation falls back to a NumPy path when the extension is unavailable.

Payload

The top-level payload schema is hybrid_digital_analog_v1:

{
    "schema": "hybrid_digital_analog_v1",
    "platform": "circuit_qed",
    "duration": 1.25,
    "digital_time": 1.25,
    "partition": {
        "n_couplings": 5,
        "n_analog_couplings": 2,
        "n_digital_couplings": 3,
        "assignments": [
            {"source": 0, "target": 1, "coefficient": 0.8, "route": "analog"},
        ],
    },
    "schedule": [
        {"route": "analog_native", "payload": {"schema": "exchange_resonator_v1"}},
        {"route": "digital_residual", "payload": {"schema": "digital_residual_qasm2_v1"}},
    ],
}

The analog schedule item embeds the native analog payload described in the analog backend documentation. The digital schedule item contains OpenQASM 2 for the residual Trotter circuit, plus depth, size, Trotter-step, and residual-presence metadata.

Backend Registry

The built-in backend registry exposes the compiler as hybrid_digital_analog:

from scpn_quantum_control.hardware import get_backend

backend = get_backend("hybrid_digital_analog")
program = backend.compile(problem, duration=1.0, max_analog_couplers=1)

Third-party provider adapters can consume HybridDigitalAnalogProgram and translate the two schedule blocks into provider-native analog controls and digital circuit submissions.