Hardware Guide

For established technologies such as standard HEMTs, room-temperature isolators, circulators, filters, couplers, and terminators, there are numerous large, established manufacturers in the market capable of providing a wide range of product options and large-scale production capabilities.

For specialized components required for cutting-edge applications like quantum computing—such as Josephson Traveling-Wave Parametric Amplifiers (J-TWPAs), cryogenic isolators/circulators operating at the mK level, specialized cryogenic filters, and advanced HEMT architectures—the supply chain is primarily dominated by specialized startup companies.

Other requirements, such as thermalization (heat sinking), rely on system-level integrated solutions or custom designs rather than single, off-the-shelf components. Effective cryogenic thermalization of outer conductors involves a combination of specialized cables, connectors, and thermal management hardware (like thermal straps).

Advances in quantum computing depend heavily on this specialized ecosystem of component startups. For any researcher involved in building quantum hardware, the following vendors are worth considering:

Startup Name (Click for Link)	Country/Region	Main Component Focus	Key Technology/Innovation	Notes
Silent Waves	France	TWPA	Josephson junctions, Kerr Inversion, ultra-low-noise amplification	Founded in 2022, with a strong research background
QuantWare	Netherlands	TWPA, QPU	J-TWPA (Crescendo-S), Scalable QPUs	Founded in 2021, a spin-off from TU Delft/QuTech
QET Sweden	Sweden	TWPA	Vidar TWPA, 4 GHz bandwidth, multi-TWPA integration	Founded in 2024, spin-off from Chalmers University, collaborates with SCALINQ
QphoX	Netherlands	TWPA, Quantum Transducers	AI-TWPA-C, Microwave-to-optical quantum transduction	Founded in 2021
Finwave Semiconductor	USA	GaN HEMT	GaN-on-Si FinFET, E-mode MISHEMT	Formerly Cambridge Electronics (2012), a spin-off from MIT
Metamagnetics	USA	Cryogenic Isolators/Circulators	Self-biased miniaturized components	Founded in 2009
Quantum Machines	Israel	Cryogenic Low-Pass Filters	QFilter-II, mK-level electron temperature filtering	A global leader in quantum control systems
SCALINQ	Sweden	Quantum Hardware Packaging, Cryo LPF	Multi-qubit packaging solutions (LINQER)	Based on research from Chalmers University, collaborates with QET Sweden

Startup & Product Example	Product Image (Images from official websites)
Silent Waves Ultra-low noise superconducting amplifiers
QuantWare Crescendo-S: Josephson travelling wave parametric amplifier (J-TWPA)
Metamagnetics Advanced Microwave/mm-wave Circulator and Isolator Solutions
Quantum Machines QFilter-II: Compact Cryogenic Low-Pass Filter

Originally written in Chinese by the author, these articles are translated into English to invite cross-language resonance.