IBM Quantum Backend Drift Monitor with n8n, Sheets & Gmail

IBM Quantum backend drift monitoring—automated daily Bell tests with live calibration logging

This n8n workflow finds the least-busy IBM Quantum backend each morning, selects the healthiest qubit pair using live calibration data, runs a Bell state test, logs every run to Google Sheets, and emails you a short OpenAI-written update—so you can catch quantum backend drift as it happens.

What this workflow does

• Loads your run settings every morning from a single Set node: shot count, minimum qubits, a CZ error ceiling, reserved QPU seconds to protect your plan, and a tag to group runs.
• Protects your QPU budget: it checks how much QPU time your IBM Quantum plan has left. If you’re below your reserve threshold, it emails you and stops, preventing quiet drain during an active schedule.
• Chooses the least-busy backend right now: it asks IBM Quantum which backend is least busy and downloads that backend’s live calibration report (refreshed by IBM roughly every few hours and continuously changing).
• Scores qubit pairs from live calibration data: a Code node ranks candidate two-qubit links. For each CZ pair, it adds gate error to the readout error of both qubits, sorts results, and filters out links that look broken. On a 156-qubit Heron processor, it can rank around 350 candidate pairs before selecting.
• Executes a Bell test in the backend’s native gate set: the workflow writes the Bell state circuit using rz, sx, and cz on the physical qubit indices, avoiding reliance on transpilation.
• Logs and reports the outcome: every run is written to Google Sheets, and Gmail sends you a concise note describing what changed (authored with OpenAI).

Use cases

• SaaS operators monitoring cost control for IBM Quantum usage with a “QPU seconds reserve” guardrail.
• Automation engineers tracking daily quantum processor drift using live calibration-driven qubit selection.
• Teams validating which CZ pair quality shifts over time via Sheets logs and email alerts.

Technical details

• n8n nodes: if, set, code, gmail, sticky note, google sheets
• Integrations: IBM Quantum backend selection + live calibration report, Google Sheets logging, Gmail notifications, OpenAI-written summary