Qblox builds open quantum control platform on QuantWare Soprano-D5 QPU
Qblox has built a Qubit Lab centered on QuantWare’s superconducting QPU, the Soprano-D5, and is evaluating control electronics noise, flux control, and gate fidelity under operating conditions. The company has also demonstrated a two-qubit gate that combines direct flux biasing with digital pre-compensation.
Announcement summary
The Qubit Lab integrates the Soprano-D5 with a Maybell cryostat, Delft Circuits wiring, Qblox control hardware, and QuantrolOx software into a single experimental environment. The setup is designed to develop and validate new control methods and algorithms directly on a quantum processor.
Using this environment, Qblox is evaluating the noise levels of control electronics, flux control, and gate fidelities. The company reports demonstrating a high-fidelity two-qubit gate by combining direct flux biasing with digital pre-compensation, although it has not disclosed specific fidelity numbers.
Qblox presented results at the 2025 and 2026 APS March Meetings on flux biasing without a bias‑T and on low‑noise operation of the Qubit Control Module at the sweet spot. Qblox’s publicly available notebooks have also been validated on the Soprano-D5.
Key points
- Integrated a multi‑vendor experimental environment combining QPU, cryogenics, wiring, control hardware, and software
- Uses the Soprano-D5 as a common hardware platform to evaluate noise, flux control, and gate fidelities
- Demonstrated a high‑fidelity two‑qubit gate using direct flux biasing with digital pre‑compensation, but did not disclose fidelity figures
- Validated all publicly available Qblox notebooks on the Soprano-D5
- Plans to expand the platform by adding the 21‑qubit Contralto-D21 to support larger, more complex experiments
Technical and business implications
This example demonstrates that quantum control techniques can be evaluated on real hardware within an environment that combines quantum processors, peripherals, control electronics, and software from different vendors. Using a stable QPU as a common testbed could make it easier to iterate on control electronics and system‑integration methods. However, quantitative performance improvements, deployment costs, comparisons with alternative approaches, and the potential scale of commercial roll‑out cannot be determined from this article alone.
What to watch next
The next focus will be whether the current control precision and low‑noise performance can be maintained after incorporating the 21‑qubit Contralto‑D21. Publication of quantitative metrics such as two‑qubit gate fidelities and reproducibility across repeated cooldowns would enable a more concrete assessment of the platform’s performance. Additionally, operational results from the multi‑vendor configuration and any deployment cases beyond research use will be important signals for commercial viability.
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