Spanish quantum networking startup Arq Quantum Technologies has raised $1.4 million in a pre-seed funding round to accelerate the development of its long-distance quantum communication hardware. The investment was led by early-stage venture capital firm Ground State Ventures, with participation from Big Sur Ventures.
Founded in 2025 by prominent quantum scientists Samuele Grandi and Emanuele Distante, the company will use the capital to build a state-of-the-art laboratory and advance the reproducibility and reliability of its next-generation quantum memory devices.
Scaling Long-Distance Quantum States via Solid-State Multiplexing
Just as classical internet networks rely on boosters to transmit light signals over long distances, the quantum internet requires specialized quantum repeaters. Over long fiber-optic distances, single photons carrying delicate quantum information (qubits) suffer from attenuation and scattering. However, classical optical amplifiers cannot copy or boost these signals due to the no-cloning theorem, which states that an unknown quantum state cannot be replicated without being destroyed.
To bypass this physical barrier, quantum repeaters must capture, store, and swap entanglement across segment boundaries. Arq’s hardware platform addresses this challenge through a highly scalable, multiplexed architecture:
- Rare-Earth Doped Crystal Memories: Arq’s repeaters combine high-performance photon-pair sources with quantum memories based on solid-state, rare-earth doped crystals. These crystals act as temporary atomic storage units, preserving the phase and polarization of incoming photons.
- Temporal and Spectral Multiplexing: Traditional repeaters process and store only one photon at a time, creating a massive throughput bottleneck. Arq’s multiplexing technology allows the memory to store and retrieve multiple distinct optical channels simultaneously, dramatically increasing entanglement generation rates.
- Telecom-Compatible Interconnects: The system is engineered to interface directly with existing commercial telecom fiber-optic infrastructure at room temperature and cryogenic boundaries, eliminating the need for complex wavelength transduction.
By merging solid-state quantum memories with high-speed multiplexing, Arq’s repeaters aim to reduce the hardware footprint and capital expenditure required to connect quantum computers. Prior to founding the company, Grandi and Distante demonstrated key milestones in academic settings, including the first multiplexed, telecom-compatible quantum repeater, light-matter entanglement over tens of kilometers of metropolitan fiber, and a coherent quantum gate between remote atoms in optical cavities.
The funding secures the necessary runway to translate these experimental breakthroughs into deployable, industrial-grade network infrastructure for telecommunications, financial networks, and defense sectors.
Review the official funding rollout announcement here.
July 16, 2026
