Barcelona · Spin-off from ICFO

Hardware for the quantum internet.

ARQ Quantum Technologies builds rare-earth–based quantum repeater nodes — the foundational hardware that will let entanglement travel between cities, countries, and continents.

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Technology & Vision

Rare-earth repeater chains that connect quantum processors.

A useful quantum internet requires that entanglement be distributed over hundreds of kilometres — far beyond the reach of direct fibre transmission. ARQ's repeater architecture is designed around the same ICFO quantum-memory physics that first enabled long-distance teleportation.

Our platform uses double resonant cavity SPDC sources to generate narrowband entangled photon pairs, and Pr³⁺:YSO quantum memories to store them with long coherence and high multimode capacity.

Each repeater chain spans two quantum processors with two synchronized DRC SPDC sources, two Pr³⁺:YSO memory stations, and an entanglement swap in the middle. This is how ICFO physics becomes a real repeater link for metropolitan-scale networks.

Platform
Rare-earth doped crystals
Channel
Telecom O / C band
Multiplexing
Temporal & spectral
Lineage
ICFO · QIA · QSNP
01
Massively multiplexed nodes
Push memory bandwidth and mode count to the levels required for kHz-rate entanglement distribution between metropolitan nodes.
02
Telecom-native operation
Lock the network layer to standard fibre infrastructure via integrated frequency conversion — no exotic channels, no custom fibre.
03
From lab to field
Engineer repeater nodes that are rack-mountable, remotely operable, and ready to integrate into European quantum network testbeds.
Coming soon

First-generation node · deeper technical disclosures · partnership programme.

We’re heads-down on the first ARQ repeater node and expanding the team in Barcelona. Detailed specs, application notes, and collaboration opportunities will land here soon.

Our Team

A core of quantum-optics builders, fresh from the lab.

ARQ was incorporated in September 2025 as a deep-tech spin-off from the Quantum Photonics group at ICFO. The founding team brings a decade of published work on quantum memories, single-photon sources, and long-distance entanglement experiments.

We’re growing — quantum optics engineers, control & FPGA developers, cryogenics, and integration specialists. If that’s you, come say hello.

ARQ team group photo

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