Arq raises $1.4M to build the repeaters behind a quantum internet
The Spanish startup is developing quantum memories and photon sources intended to carry quantum information over long-distance fibre networks.
Arq has raised $1.4M to work on one of the least visible but most important pieces of a future quantum internet: the repeater hardware needed to move quantum information across long distances.
What happened
The Spanish quantum-technology startup closed a $1.4M pre-seed round led by Ground State Ventures, with Big Sur Ventures participating.
Founded in 2025 by quantum scientists Samuele Grandi and Emanuele Distante, Arq is developing quantum repeaters for fibre networks. Its architecture combines photon-pair sources with quantum memories based on rare-earth-doped crystals.
The financing will help the company establish a laboratory and improve the reliability and reproducibility of its memory devices.
Why it matters
Conventional internet signals can be amplified as they travel. Quantum information cannot be copied in the same way, because measuring or duplicating a quantum state changes it.
Repeaters are therefore necessary to extend quantum communication beyond short links. They must store fragile quantum states, coordinate entanglement and operate with extremely low error rates.
The bigger picture
Arq is tackling foundational hardware rather than building software around existing quantum computers. That gives it long-term strategic relevance, but also means commercialisation may take years.
The company must first prove that its components work consistently in laboratory conditions, then integrate them into practical networks and reduce cost enough for deployment. A functioning quantum internet remains uncertain and distant, but reliable repeaters would be essential infrastructure if the field progresses.