Quantinuum¶

Run benchmarks on Quantinuum H-series trapped-ion quantum computers through the NEXUS platform.

Prerequisites¶

A Quantinuum NEXUS account
NEXUS credentials (username and password)

Setup¶

1. Get NEXUS Credentials¶

Register at Quantinuum NEXUS
Note your username and password

2. Configure Environment¶

Add to your .env file:

QUANTINUUM_NEXUS_USERNAME="<your-username>"
QUANTINUUM_NEXUS_PASSWORD="<your-password>"
QUANTINUUM_NEXUS_PROJECT_NAME="metriq-gym"

# Optional: optimization level for compilation (default: 1)
QUANTINUUM_NEXUS_OPT_LEVEL="1"

The first time you use Quantinuum, you must complete a manual login workflow:

qnx login

Follow the prompts to authenticate and link your account.

Discovering Devices¶

Quantinuum offers H-series hardware, emulators, and syntax checkers. To see currently available devices:

from qbraid.runtime import load_provider

provider = load_provider("quantinuum")
for device in provider.get_devices():
    print(f"{device.id}: {device.status}")

Or check the NEXUS portal for current device availability.

Tip

Use syntax checkers (devices ending in SC) to validate circuits before running on hardware. They're free and instant.

Usage¶

Dispatch to Quantinuum Hardware¶

mgym job dispatch metriq_gym/schemas/examples/wit.example.json \
    --provider quantinuum --device H1-1

Dispatch to Emulator¶

mgym job dispatch metriq_gym/schemas/examples/wit.example.json \
    --provider quantinuum --device H1-1E

Poll Results¶

mgym job poll <JOB_ID>

Pricing¶

Quantinuum uses H-series Quantum Credits (HQCs) for billing. See Quantinuum's documentation for current pricing details.

Use mgym job estimate to estimate HQCs before running:

mgym job estimate config.json --provider quantinuum

NEXUS Projects¶

Jobs are organized into NEXUS projects. Set the project name:

QUANTINUUM_NEXUS_PROJECT_NAME="my-project"

Compilation Optimization¶

Control TKET compilation optimization:

# Levels: 0 (none), 1 (default), 2 (aggressive)
QUANTINUUM_NEXUS_OPT_LEVEL="2"

Higher levels may reduce gate counts but increase compilation time.

Troubleshooting¶

If you see authentication errors, re-run:

qnx login

HQC Limits¶

Check your HQC balance in the NEXUS portal. Jobs exceeding your balance will fail.

Compilation Errors¶

Some circuits may not compile efficiently for trapped-ion hardware. Try: - Reducing circuit depth - Using optimization level 2 - Checking for unsupported operations