Silent Waves

Silent Waves is a French quantum technology company focused on the readout layer of superconducting quantum computers. It designs, manufactures and commercializes traveling-wave parametric amplifiers (TWPAs), the ultra-low-noise cryogenic amplifiers that sit at the front of the readout chain and determine how faithfully the state of a qubit can be measured. The company positions its products around a simple promise — "Reliable by design" — and around the engineering requirements of real quantum systems: high net gain, wide bandwidth, high saturation power and noise performance close to the quantum limit. Silent Waves' product family is built around the Argo, its flagship photonic-crystal TWPA, which uses a photonic gap engineered into the dispersion relation to achieve high gain over a bandwidth exceeding 1.5 GHz. The Argo is flux-insensitive, requires no DC current source and is powered by a microwave source, making it convenient to install and usable in applications involving magnetic fields. Around this core device the company has built a portfolio for different integration needs: the Carthago, a highly tunable TWPA based on Kerr-reversal physics for flexible experimental setups; the Zephyr, which integrates the Argo with an on-chip pump coupler to reduce cabling and footprint in space-constrained cryostats; and the Dreadnought, a single-shot plug-and-play readout chain that integrates the cryogenic microwave electronics together with the TWPA. The company sells to the quantum computing hardware ecosystem rather than to end consumers. Its amplifiers are aimed at multiplexed qubit readout, where readout fidelity and reliability are critical, and where the TWPA enables multiplexing and supports scalable readout architectures. Silent Waves states that it has been a partner to Rigetti, and it has joined the SUPREME consortium, indicating engagement with European quantum research programmes. Products are characterized cryogenically at 20 mK before shipment, and each unit is delivered with a characterization report. Silent Waves is a private company based in France. It operates in the specialized, technically demanding niche of cryogenic quantum electronics, where its differentiation rests on device physics — dispersion engineering, Kerr-reversal operation and on-chip integration — combined with a commercial focus on ease of installation, market-aligned pricing and reliable operation in dilution refrigerators.

Silent Waves is a French quantum readout technology company. It emerged in the specialized field of cryogenic quantum electronics, where the performance of a superconducting quantum computer depends not only on the qubits themselves but also on how precisely their states can be measured. The readout chain of such a machine relies on ultra-low-noise amplifiers, and the traveling-wave parametric amplifier (TWPA) has become a key device for reaching the near quantum-limited noise performance required for high-fidelity, multiplexed qubit readout. Silent Waves built its business around designing, manufacturing and commercializing TWPAs. Its first traveling-wave parametric amplifier, the Argo, became the company's flagship product. The Argo is a photonic-crystal TWPA: to achieve high gain over a bandwidth exceeding 1.5 GHz, the device introduces a feature in the dispersion relation — a photonic gap engineered by spatially modulating the Josephson junctions — which supports phase-matching between pump, signal and idler. The resulting gain gap of roughly 0.4 GHz can be customized, with the standard gap frequency position between 6 and 7 GHz and customization available between 4 and 8 GHz. The Argo is flux-insensitive, requires no DC current source, is powered by a microwave source, and is characterized at 20 mK before shipment. The company expanded from this single device into a portfolio addressing different integration and flexibility requirements. The Carthago, based on Kerr-reversal physics, delivers continuous high gain across a very wide bandwidth while maintaining low noise and high saturation power, and its tunability suits experimental setups requiring maximum flexibility. The Zephyr integrates the Argo TWPA with an on-chip pump coupler, reducing the number of connectors and cables, minimizing space requirements and insertion losses, and making it a plug-and-play solution for enhanced readout performance; it offers more than 15 dB net gain, 2 GHz bandwidth, saturation power of -100 dBm at 20 dB gain and added noise of about 1.5 SQL. The Dreadnought goes further, integrating the entire cryogenic microwave electronics chain together with the TWPA as a single-shot, plug-and-play solution for high-fidelity qubit readout. Silent Waves has positioned itself within the quantum hardware ecosystem as a component supplier and partner rather than a system vendor. It states that it has been a valuable partner to Rigetti, citing strong technical understanding, responsive collaboration and a commitment to supporting high-performance superconducting quantum systems. It has also joined the SUPREME consortium, indicating participation in collaborative European quantum research. The company emphasizes that its TWPAs are designed for multiplexed qubit readout, where readout fidelity and reliability are critical, and that they combine high net gain, wide bandwidth, high saturation power and near quantum-limited noise performance to support real quantum systems. Commercially, Silent Waves focuses on delivering products that provide real value to customers: state-of-the-art performance, market-aligned pricing, and engineering designed for reliable installation and operation in cryogenic environments. Its products are sold with full cryogenic characterization at 20 mK and a characterization report sent before shipment, a practice the company presents as ensuring transparency and verified performance from day one. The company is based in France and remains a private enterprise.

• Silent Waves launches the Zephyr, an integrated TWPA and pump coupler solution for compact, high-efficiency quantum readout.

• Silent Waves joins the SUPREME consortium.

• The Argo, Silent Waves' first traveling-wave parametric amplifier and flagship TWPA, is offered as a photonic-crystal device with customizable gain gap.

• The Carthago, a highly tunable TWPA based on Kerr-reversal physics, is added to the product line.

• The Dreadnought, an integrated TWPA and readout chain, is offered as a single-shot, plug-and-play solution for high-fidelity qubit readout.

Ultra-low-noise TWPA specialist for high-fidelity, multiplexed qubit readout; "Reliable by design", with state-of-the-art performance, market-aligned pricing and engineering for reliable cryogenic installation and operation.

• The Argo

  Flagship photonic-crystal traveling-wave parametric amplifier for high-fidelity qubit readout. Typical gain >15 dB, bandwidth 1.5 GHz, saturation power >-100 dBm at 20 dB, near quantum limited at maximum gain. Flux insensitive, no magnetic bias, SMA connectors, 50 Ω matched, plug & play, powered by a microwave source without DC biasing. Standard gap frequency position between 6 and 7 GHz, customizable between 4 and 8 GHz. Full characterization performed at 20 mK with a report sent before shipment. Available in customizable configurations and as the pre-tuned Argo Essential.

• The Carthago

  A highly tunable TWPA based on Kerr-reversal physics, delivering continuous high gain across a very wide bandwidth while maintaining low noise and high saturation power. Its tunability makes it an ideal TWPA solution for experimental setups requiring maximum flexibility.

• The Zephyr

  An integrated TWPA and pump coupler solution that combines the Argo TWPA with an on-chip pump coupler. Max net gain >15 dB, bandwidth 2 GHz, saturation power -100 dBm at 20 dB gain, added noise ~1.5 SQL. 50 Ω matched, no magnetic bias, compact form-factor, easy to install, powered by a microwave source without DC biasing. Full characterization at 20 mK with a report sent before shipment.

• The Dreadnought

  A single-shot, plug-and-play solution for high-fidelity qubit readout that integrates the entire cryogenic microwave electronics chain plus the TWPA, simplifying installation and reducing system complexity.

1. 1Silent Waves - Traveling-Wave Parametric Amplifiers (TWPAs)silent-waves.com
2. 2Silent Waves - The Argosilent-waves.com
3. 3Silent Waves - The Zephyrsilent-waves.com
4. 4Silent Waves - Productssilent-waves.com
5. 5Silent Waves - Wikidatawikidata.org