Qunnect Team Generates, Distributes, Preserves Entangled Photons Over 34 Kilometers of GothamQ Network Fiber

Insider Brief

• Qunnect announced that GothamQ, its quantum network that uses existing commercial fiber optic cable, surpassed previous performance metrics.
• The network distributed polarization-based quantum entanglement while delivering exceptionally high rates of preservation and fidelity.
• The hardware instruments generated, distributed and preserved entangled photons over 34 kilometers of fiber within the GothamQ network.
• Image: Schematic of the 34km loop within the GothamQ testbed used for the study. The inset diagrams show the experimental apparatus prior to photons entering and exiting the deployed fiber. (Qunnect)

PRESS RELEASE — Qunnect, a leader in quantum-secure networking technology, announced that GothamQ, its quantum network utilizing existing commercial fiber optic cable, surpassed previous performance metrics in enabling the distribution of polarization-based quantum entanglement while delivering exceptionally high rates of preservation and fidelity. This technical achievement signifies the viability of Qunnect’s quantum networking components to perform entanglement-based protocols over prolonged durations in real-world environments.

“GothamQ’s performance as a stable, automated network that can support high-quality entanglement distribution networking protocols represents a major step forward in unlocking future applications like distributed quantum sensing and computing,” said Noel Goddard, CEO of Qunnect. “As we celebrate World Quantum Day, we are proud to showcase Qunnect’s first-in-class hardware as an example of the progress made in turning experimental innovations into commercial products.”

Unlike most quantum networks, Qunnect uses atoms at room temperature to generate polarization entangled photons, since these qubits are native to other quantum devices such as sensors and computers. By constructing a stable network to distribute polarization qubits, Qunnect has demonstrated a path forward for other quantum networks to host applications beyond secure communications.

For this demonstration, the Qunnect team used its hardware instruments to generate, distribute, and preserve entangled photons over 34 kilometers of fiber within the GothamQ network. Its QU-SRC maintained generation rates between one to ten million polarization-entangled photon pairs per second. Meanwhile, the QU-APC preserved the fidelity of the transmitted photons through an automated protocol, minimizing the quantum bit error rate. The result was a record-breaking 99.84% network uptime over 15 days of continuous operation. During that time, the team:

• Distributed and preserved 500,000 polarization-entangled pairs per second in commercial-grade fiber channels with 17dB of transmission loss
• Maintained a quantum bit error rate below 2.5%

The full test results are published in a manuscript posted on ArXiv today (https://arxiv.org/abs/2404.08626), in celebration of World Quantum Day 2024.

Unlike traditional quantum networks, Qunnect chose to encode quantum bits of information with light polarization for this test, since polarization qubits are native to other quantum devices such as quantum sensors and computers. By constructing a stable network to distribute polarization qubits, Qunnect has demonstrated a path forward for other quantum networks to host applications beyond secure communications.

“This work demonstrates that the field of entanglement distribution networking is ready to transition from proof-of-concept experiments to the era of reliable, 24/7 operation.” Said Mehdi Namazi. “And important to note, we used polarization qubits. Qubits that are highly practical for transactions the end nodes, yet notoriously hard to preserve in long, deployed fiber optic channels.”

As part of its mission to transform traditional telecom infrastructure into quantum networks, Qunnect’s products are all housed in standard server racks. They are currently installed and operating on testbeds around the world. Later this year, Qunnect plans to release the industry’s first full-rack quantum networking system to enable users to replicate the entanglement distribution protocols demonstrated in this announcement.