Implementing Quantum Technology in High-Traffic Networks

Researchers at Northwestern University (USA) have made a significant breakthrough in quantum communication by successfully teleporting a quantum state of light—a qubit carried by a photon—through approximately 30 kilometers of optical fiber while simultaneously transmitting high-speed classical data traffic. Key details include: - The fiber length used was around 30.2 km. - It carried a classical signal of approximately 400 Gbps in the C-band alongside the quantum channel. - The quantum channel operated in the O-band, utilizing special filtering and narrow-temporal/spectral techniques to shield delicate photons from noise, such as spontaneous Raman scattering from the classical channel. This experiment confirms that quantum teleportation of a quantum state can coexist with classical internet traffic in the same fiber infrastructure. It's important to clarify that "teleportation" in quantum communication does not involve moving the physical photon or "beaming" objects as depicted in science fiction. Instead, it refers to the transfer of the quantum state of a qubit from one location to another using an entanglement-based protocol, coupled with classical communication. The original qubit is destroyed during this process and recreated at the destination. While quantum teleportation enables inherently secure quantum communication channels—since measurement disturbs quantum states—practical deployment still faces challenges, including node security, classical channel security, side-channels, and error rates. This marks a significant step toward quantum-secure networks, though it is not yet a complete "unhackable" solution. This experiment suggests that we may not require entirely separate fiber infrastructure dedicated solely to quantum communications; existing telecom fiber could be effectively utilized. It enhances the feasibility of developing quantum networks and, eventually, a "quantum internet" that integrates with classical infrastructure. From a security and cyber perspective, it supports the architecture of quantum-secure communications, including quantum key distribution and entanglement-based signaling. Overall, this represents a major technological milestone in photonics, quantum information science, and telecom integration.

Breakthrough for the #quantum internet: For the first time a major telco provider has successfully conducted entangled photon experiments - on its own infrastructure. ➡️ 30 kilometers, 17 days, 99 per cent fidelity. Our teams at T-Labs have successfully transmitted entangled photons over a fiber-optic network. Over a distance comparable to travelling from Berlin to Potsdam. The system automatically compensated for changing environmental conditions in the network.   Together with our partner Qunnect we have demonstrated that quantum entanglement works reliably. The goal: a quantum internet that supports applications beyond secure point-to-point networks. Therefore, it is necessary to distribute the types of entangled photons. The so-called qubits, that are used for #QuantumComputing, sensors or memory. Polarization qubits, like the ones used for this test, are highly compatible with many quantum devices. But: they are difficult to stabilize in fibers.   From the lab to the streets of Berlin: This success is a decisive step towards the quantum internet. 🔬 It shows how existing telecommunications infrastructure can support the quantum technologies of tomorrow. This opens the door to new forms of communication.   Why does this matter for people and society?   🗨️ Improved communications: The quantum internet promises faster and more efficient long-distance communications. 🔐 Maximum security: Entanglement can be used in quantum key distribution protocols. Enabling ultra-secure communication links for enterprises and government institutions 💡Technological advancement: high-precision time synchronization for satellite networks and highly accurate sensing in industrial IoT environments will need entanglement.   Developing quantum technologies isn’t just a technical challenge. A #humancentered approach asks how these systems can be built to serve real needs and be part of everyday infrastructure. With 2025 designated as the International Year of Quantum Science and Technology, now is the time to move from research to readiness. Matheus Sena, Marc Geitz, Riccardo Pascotto, Dr. Oliver Holschke, Abdu Mudesir

Under the streets of Manhattan and Brooklyn. Through 60 Hudson, one of the most connected carrier hotels in the world. Real quantum entanglement at scale on 17.6 km of standard telecom fiber. With swapping rates 3+ orders of magnitude beyond prior efforts and fidelity above 99%. This is the full quantum networking stack coming together — hardware, protocol, control, orchestration. Most importantly, we ran this without the shared laser crutch that makes lab experiments unscalable by design. This real-world demo used fully independent quantum sources at each endpoint. With Cisco's quantum software stack handling timing coordination at picosecond precision across three geographically separated nodes using the White Rabbit protocol. Qunnect's room-temperature hardware at the edges. And cryogenic equipment only at the hub for efficiency. Any new nodes could be added to this network without touching the sync infrastructure. And with clean control and data plane separation.   Applying design patterns that scaled the classical internet to quantum networking. I wrote about what this milestone means and how it leads us one step closer to our vision of a quantum data center network, on the Cisco blog today. 🔗 Link in comments. 📸 Photo of Manhattan from the Brooklyn end, by me.

𝗛𝗼𝘄 𝘁𝗼 𝗔𝗽𝗽𝗹𝘆 𝗤𝘂𝗮𝗻𝘁𝘂𝗺-𝗜𝗻𝘀𝗽𝗶𝗿𝗲𝗱 𝗔𝗹𝗴𝗼𝗿𝗶𝘁𝗵𝗺𝘀 𝘁𝗼 𝗗𝗮𝘁𝗮 𝗖𝗲𝗻𝘁𝗲𝗿 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻 (𝗔𝗜𝗢𝗽𝘀 𝗪𝗶𝘁𝗵𝗼𝘂𝘁 𝗮 𝗤𝘂𝗮𝗻𝘁𝘂𝗺 𝗖𝗼𝗺𝗽𝘂𝘁𝗲𝗿) Most leaders hear “quantum” and think of it as experimental, expensive, and years away. That’s a mistake. Quantum-inspired algorithms run on classical infrastructure today and solve the hardest problem you actually have: large-scale optimization under constraints. If you run data centers, this is immediately actionable. What they actually do They convert your environment into an energy minimization problem. Instead of brute forcing every possibility, they rapidly converge on high-quality solutions across massive decision spaces. Think: • Placement • Scheduling • Routing • Thermal balancing • Power allocation Where to apply first (high ROI use cases) 1. Rack and cluster placement Model racks, power domains, cooling zones, and network topology as constraints. Objective: minimize latency + cable length + thermal hotspots. 2. GPU scheduling and utilization: Encode job priority, SLA windows, GPU affinity, and network contention. Objective: maximize utilization while reducing idle burn and queue latency. 3. Thermal + power balancing: Integrate cooling capacity, airflow constraints, and power density. Objective: flatten hotspots without over-provisioning. 4. Network traffic shaping Model east-west traffic flows and oversubscription ratios. Objective: Reduce congestion and packet loss under peak load. How to implement (practical workflow) Step 1: Define variables • Binary: placement decisions, routing paths • Continuous: load, temperature, power draw Step 2: Define constraints • Power caps per rack and row • Cooling limits by zone • Network bandwidth ceilings • SLA requirements Step 3: Build the objective function. Combine into a weighted cost function: • Latency • Energy consumption • Thermal deviation • Resource fragmentation Step 4: Select a solver. Use simulated annealing or related heuristics to explore the solution space efficiently. Step 5: Iterate with real telemetry. Feed in live data: • DCIM • BMS • Scheduler metrics: Continuously refine the model. What “good” looks like • 10–25% improvement in GPU utilization • Lower east-west congestion without network upgrades • Reduced thermal excursions • Faster schedule generation cycles Where most teams fail • Overfitting the model before validating its impact • Ignoring real-time telemetry • Treating this as a one-time optimization instead of a continuous system Bottom line: You don’t need quantum hardware to get quantum-level thinking. You need a structured optimization model and the discipline to iterate it against real operating data. If you’re running >10MW environments and not doing this, you’re leaving efficiency and margin on the table. #DataCenters #AIInfrastructure #GPU #Optimization #HighPerformanceComputing #Cloud #Infrastructure #DigitalTransformation

PHOTON-INTERFACED SCALABLE QUANTUM NODES LINKING LIGHT AND MATTER The photon‑interfaced ten‑qubit register of trapped ions constitutes a potential advance in the development of scalable quantum network nodes. In this architecture, each ion in a ten‑qubit linear chain is individually entangled with a propagating photon, producing a sequential train of ion–photon Bell pairs with high fidelity. Previous experiments had only achieved this capability for one or two ions, making the extension to a full ten‑qubit register a meaningful step toward practical matter‑to‑light interfaces for distributed quantum information processing. The system operates by dynamically transporting ions into the mode of an optical cavity and driving a cavity‑mediated Raman transition that generates a single photon entangled with the ion’s internal qubit state. This procedure yields a time‑ordered photonic qubit stream in which each photon carries the quantum information of a distinct ion. The significance of this work lies in its direct response to a central challenge in quantum networking: the need to map the quantum state of a multi‑qubit matter register onto a set of photonic qubits that can propagate through optical fiber with low loss. Trapped ions serve as exceptionally coherent stationary qubits, but they cannot be transported between processors. Photons, by contrast, function as low‑loss flying qubits capable of transmitting quantum information over long distances. Ion–photon entanglement is therefore the essential mechanism for linking spatially separated ion‑based processors. Scaling this interface to ten ions establishes a clear path toward high‑rate, multiplexed entanglement distribution. This scaling is particularly relevant in light of recent long‑distance demonstrations in which multiple ions, each entangled with its own photon, were used to increase entanglement distribution rates over fiber links exceeding one hundred kilometers. Generating a rapid sequence of entangled photons—each correlated with a different ion—enables temporal multiplexing, which is indispensable for overcoming fiber loss and improving heralded entanglement rates. The ten‑ion photon‑interfaced register provides precisely the type of multiplexed matter‑to‑light source required for such architectures. Despite its importance, several technical challenges remain. Photon detection probabilities must be increased to support long‑distance networking without excessive repetition rates. Sequential ion shuttling introduces timing overhead and potential motional heating, and cavity alignment and stability become increasingly demanding as the register size grows. Maintaining spectral and temporal indistinguishability across the full photon train is essential for multi‑node entanglement generation and remains an active area of optimization. These challenges, however, represent engineering refinements rather than fundamental limitations. #DOI: https://lnkd.in/e5HRus5e

Quantum teleportation coexisting with classical communications in optical fiber https://lnkd.in/gcSWCpup Abstract: The ability for quantum and conventional networks to operate in the same optical fibers would aid the deployment of quantum network technology on a large scale. Quantum teleportation is a fundamental operation in quantum networking, but has yet to be demonstrated in fibers populated with high-power conventional optical signals. Here we report, to the best of our knowledge, the first demonstration of quantum teleportation over fibers carrying conventional telecommunications traffic. Quantum state transfer is achieved over a 30.2-km fiber carrying 400-Gbps C-band classical traffic with a Bell state measurement performed at the fiber’s midpoint. To protect quantum fidelity from spontaneous Raman scattering noise, we use optimal O-band quantum channels, narrow spectro-temporal filtering, and multi-photon coincidence detection. Fidelity is shown to be well maintained with an elevated C-band launch power of 18.7 dBm for the single-channel 400-Gbps signal, which we project could support multiple classical channels totaling many terabits/s aggregate data rates. These results show the feasibility of advanced quantum and classical network applications operating within a unified fiber infrastructure.

Quantum Teleportation Achieved Over 79 km of Standard Internet Fiber Introduction Quantum teleportation has moved from isolated laboratory experiments into real-world infrastructure. German physicists have successfully teleported quantum information over 79 kilometers of standard fiber-optic cables, demonstrating that quantum communication can coexist with everyday internet traffic and bringing the concept of a practical quantum internet significantly closer. The Breakthrough Researchers at the Ferdinand-Braun-Institut achieved quantum teleportation using existing telecom infrastructure. • Quantum states were teleported over 79 km of conventional fiber-optic cable • Transmission occurred at standard telecom wavelengths around 1550 nanometers • Quantum signals coexisted with classical internet data without interference • The work was conducted under the EU Quantum Flagship program How It Works The experiment relied on established quantum principles implemented in a novel way. • Entangled photons were generated using indium gallium arsenide quantum dots • Quantum entanglement allowed the state of one particle to be transferred to another at a distance • Operating at telecom wavelengths minimized signal loss and noise • Careful stabilization preserved fragile quantum states across long distances Why This Is Different Previous teleportation experiments required specialized or dedicated infrastructure. • No custom fiber lines were needed • No disruption to normal data traffic occurred • The approach dramatically reduces cost and complexity • It demonstrates realistic scalability beyond the lab Implications for Security and Networks The findings have immediate relevance for secure communications. • Enables quantum key distribution resistant to future quantum attacks • Supports hybrid networks carrying classical and quantum data side by side • Advances the feasibility of quantum repeaters for global-scale networks • Strengthens applications in finance, defense, and critical infrastructure Why It Matters This achievement marks a turning point for quantum communications. By proving that quantum teleportation works over standard internet fiber, researchers have lowered one of the biggest barriers to deployment. Instead of rebuilding global networks from scratch, quantum security and computation can be layered onto existing infrastructure, accelerating timelines toward a secure, quantum-enabled internet and redefining how information may be protected in the decades ahead. I share daily insights with 35,000+ followers across defense, tech, and policy. If this topic resonates, I invite you to connect and continue the conversation. Keith King https://lnkd.in/gHPvUttw

Quantum computers have the potential to solve complex problems that are beyond the capabilities of classical supercomputers. Current methods ("point-to-point" ) involve complex intermediary circuits, which introduce noise and loss. To overcome these challenges, Massachusetts Institute of Technology researchers have developed a new interconnect device that supports scalable, "all-to-all" communication. This allows all superconducting quantum processors in a network to communicate directly with each other. Key Takeaways: 💻 The new device supports scalable, "all-to-all" communication among quantum processors. ⚛️ Demonstrates remote entanglement, a key step toward developing a powerful, distributed network of quantum processors. ⚡ The interconnect can send photons at different frequencies, times, and in two propagation directions, enhancing network flexibility and throughput. 📈 Achieved over 60% photon absorption efficiency using a reinforcement learning algorithm. 🪴 This technology could be expanded to other kinds of quantum computers and larger quantum internet systems, essential for scalable quantum networks Read more at https://lnkd.in/efj23u6t Research from Aziza Almanakly , Beatriz Yankelevich, Max Hays, Bharath Kannan, Reouven Assouly, Alex Greene, Michael Gingras, Bethany Niedzielski Huffman, Hannah Stickler, Mollie Schwartz, Kyle Serniak, Joel I-Jan Wang, Terry P. Orlando, Simon Gustavsson, Jeffrey A. Grover, and Will Oliver in the MIT Lincoln Laboratory MIT Department of Physics Massachusetts Institute of Technology

⚛️ Quantum Networking Fundamentals: From Physical Protocols to Network Engineering 📜 The realization of the Quantum Internet promises transformative capabilities in unconditionally secure communication, distributed quantum computing, and high-precision quantum metrology. However, transitioning from isolated laboratory experiments to a scalable, multi-tenant network utility introduces deep orchestration challenges. Current development is largely siloed within the physics and optics communities, prioritizing hardware fidelities and photon sources, while theclassical networking community lacks the architectural models required to dynamically manage these fragile quantum resources. This tutorial bridges this disciplinary divide by providing a comprehensive, network-centric view of quantum networking. We systematically dismantle the idealized assumptions prevalent in current network simulators to directly address the “simulation–reality gap,” and we recast them as explicit control-plane constraints. To bridge this gap, we establish Software-Defined Quantum Networking (SDQN) not merely as an evolutionary management tool, but as a mandatory prerequisite for scale, and we prioritize the orchestration of a symbiotic, dual-plane architecture in which classical control dictates quantum data flow. Specifically, we synthesize reference models for SDQN and the Quantum Network Operating System (QNOS) for hardware abstraction, and we adapt a Quantum Network Utility Maximization (Q-NUM) framework as a unifying mathematical lens to help network engineers reason about the inherent trade-offs between entanglement routing, scheduling, and fidelity targets. Furthermore, we analyze Distributed Quantum AI (DQAI) over imperfect networks as a case study, illustrating how physical constraints such as probabilistic stragglers and decoherence fundamentally dictate application-layer viability. Ultimately, this tutorial equips network engineers with the operational mindset and architectural tools required to transition quantum networking from a bespoke physics experiment into a programmable, multi-tenant global infrastructure. ℹ️ A. Gkelias et al - EEE Department, Imperial College, London, UK -2026

The quantum internet has been impossible for a brutal reason. Last week, I watched a $15 million quantum computer wait 10 milliseconds to talk to another $15 million quantum computer sitting 10 meters away. Ten. Milliseconds. That's 200× longer than the computation itself took. This is why Google, IBM, and every quantum company builds monolithic processors instead of networked ones. The "entanglement rate gap" makes distributed quantum computing economically insane. Until now. We discovered something wild: trapped ions can multiplex across 250,000 parallel channels. Time bins. Wavelengths. Spatial modes. But every lab was using them one at a time, like having a 1000-lane highway and driving in a single lane. Our hierarchical multiplexing architecture coordinates these resources using algorithms borrowed from how AI agents share bandwidth. Result: 847× faster quantum networking. Same hardware. The math is violent: this drops the cost per entangled qubit from $10,000 to $12. What this unlocks: - Quantum computers that scale like AWS, not like the Large Hadron Collider - City-wide quantum networks by 2028 - Distributed quantum encryption that governments can't break Oxford proved that distributed quantum computing works in February. We just made it practical. African researchers are in this race. We have to be, because quantum networks will rewire global finance, cryptography, and AI infrastructure within a decade. Paper link below. The implementation roadmap costs $400K and takes 3 years. That's accessible. The question isn't whether quantum networks will happen. It's who builds them first. 🔗 Full technical paper: https://lnkd.in/ekVh6U8y #QuantumComputing #QuantumNetworks #EmergingTech #AfricaInnovation #QuantumInternet