A transformative breakthrough from the University of Chicago’s Pritzker School of Molecular Engineering may change the landscape of quantum networking forever. Led by Assistant Professor Tian Zhong, the research team has engineered a system that could extend the quantum communication range up to a staggering 2,000 kilometers — almost 200 times the previous record. This paradigm-shifting development could finally enable a global quantum internet, connecting distant quantum processors across entire continents.

At the heart of this innovation lies an improvement in quantum coherence times — the duration for which atoms maintain their fragile quantum states when entangled over fiber optic channels. Quantum entanglement is the key to linking spatially separated quantum computers, but decoherence has traditionally limited the effective communication distance. Zhong’s team has achieved a quantum coherence time exceeding 10 milliseconds in erbium atoms embedded within specially crafted quantum materials, a leap from the mere 0.1 milliseconds typical of prior efforts.

This ten-millisecond coherence marks a critical threshold for quantum communication, theoretically enabling quantum links up to 2,000 kilometers — equivalent to connecting quantum devices between Chicago and distant cities like Salt Lake City. In some instances, coherence times extended even further, reaching an impressive 24 milliseconds, which, if realized in practical networks, could allow connections spanning over 4,000 kilometers, from Chicago to Colombia.

Intriguingly, this leap forward did not come from inventing new quantum materials but rather from a revolutionary change in how these materials were manufactured. Traditionally, rare-earth doped crystals — essential for quantum light-matter interfaces — were grown using the Czochralski method, which involves melting raw materials above 2,000 degrees Celsius and cooling them slowly into crystals. Afterward, physical sculpting is used to fashion components from these crystals, a cumbersome and imprecise process.

Instead, the University of Chicago team employed molecular-beam epitaxy (MBE), a technique more akin to 3D printing at the atomic scale. MBE deposits material layer-by-layer, allowing precise control over crystal growth and composition from the ground up. This bottom-up approach produces ultrahigh-purity materials with atomic-level precision, vastly improving the quantum coherence properties of embedded erbium ions critical for long-lived entanglement.

MBE’s application to rare-earth doped crystals is unprecedented in the quantum information domain. Working alongside materials synthesis expert Assistant Professor Shuolong Yang, Zhong’s group adapted MBE to tailor these crystals specifically for quantum networking. The high-quality epitaxial films they created admit a robust spin-photon interface operating at telecom wavelengths, perfectly suited for long-distance fiber transmission compatible with existing infrastructure.

Esteemed experts in photonics and quantum technologies have praised this innovative approach for its scalability and groundbreaking nature. Professor Hugues de Riedmatten of the Institute of Photonic Sciences, a recognized leader in quantum networking, emphasizes that this work demonstrates how precise nanofabrication methods can realize single rare-earth ion qubits with exceptional optical and spin coherence, paving the way for scalable, fiber-compatible quantum devices.

Although the theory and materials science breakthroughs are profound, Zhong and his team acknowledge that practical validation lies ahead. Their next phase involves rigorous laboratory experiments to confirm whether the extended coherence times translate into long-distance quantum communication. This will include linking two qubits housed inside separate dilution refrigerators using spooled fiber lengths simulating up to 1,000 kilometers.

Currently, Zhong’s lab is constructing a third dilution refrigerator to establish a local quantum network capable of simulating future extended quantum internet architectures. These developments represent incremental but essential milestones toward a functional quantum communication network capable of spanning urban centers, states, and ultimately the globe.

The potential implications are immense. A robust quantum internet would revolutionize secure communications by enabling unhackable quantum encryption, advance distributed quantum computing by linking remote quantum processors, and open avenues for quantum-enhanced sensing and metrology over vast distances.

This research fundamentally redefines the material science foundations of quantum networking by combining state-of-the-art nanofabrication with the physics of rare-earth ions. Its success promises to blur geographical boundaries currently limiting quantum technologies, fostering a new era where quantum computers communicate seamlessly from city to city and country to country.

Published in the prestigious journal Nature Communications on November 6, 2025, this work titled “Dual epitaxial telecom spin-photon interfaces with long-lived coherence” marks a significant milestone toward the quantum internet era. Its broad technological ramifications underscore the importance of interdisciplinary collaboration between quantum physics, materials science, and engineering.

In conclusion, the University of Chicago team’s innovative molecular-beam epitaxy fabrication method has unlocked an extraordinary increase in quantum coherence times in telecom-band erbium ions, theoretically extending the quantum communication range by two orders of magnitude. As laboratory tests advance, the dream of connecting quantum computers across continents inches closer to reality, heralding a revolution in secure communication and computational power unparalleled by classical technologies.

Subject of Research: Quantum computing; quantum coherence; rare-earth doped materials; quantum networking; molecular-beam epitaxy.

Article Title: Dual epitaxial telecom spin-photon interfaces with long-lived coherence

News Publication Date: November 6, 2025

Web References:

• Nature Communications Article
• University of Chicago Pritzker School of Molecular Engineering

References:
Gupta et al., “Dual epitaxial telecom spin-photon interfaces with long-lived coherence,” Nature Communications, November 6, 2025, DOI: 10.1038/s41467-025-64780-6

Image Credits: University of Chicago Pritzker School of Molecular Engineering / Jason Smith

Keywords: Quantum computing, Quantum information, Molecular-beam epitaxy, Quantum coherence, Telecommunication wavelength, Rare-earth doped crystals, Quantum internet, Spin-photon interface

Professor Nemoto’s commendation reflects her illustrious career and significant contributions to the field of quantum computing, particularly her pioneering work on quantum computer architecture theory. This line of inquiry is foundational to the ongoing evolution of quantum technologies, which stand on the precipice of transforming traditional computing paradigms. The recognition of her work is timely, as quantum computing is increasingly seen as a key player in addressing complex scientific problems that defy solutions through traditional computational approaches.

The award ceremony is slated to take place on April 15, where Professor Nemoto will receive the accolades from MEXT. Coincidentally, this moment of acclaim for Professor Nemoto follows last year’s award to Dr. Shizuka Shimabukuro of OIST, who also made significant contributions in the field, further highlighting the institution’s commitment to fostering scientific innovation and excellence. As these awards accumulate, they signify a vibrant period for scientific inquiry in Japan, emphasizing the nation’s dedication to leading advancements in critical areas such as quantum science.

Immersing into the depths of her research, Professor Nemoto has made profound contributions that elucidate both the feasibility and scalability of quantum computing. Her work investigates the implementation of quantum computers through various types of physical qubits, drawing upon revolutionary concepts involving photonic and superconducting qubits. By pioneering ideas surrounding computer architecture and modularization within the quantum computing framework, she has conceptualized a pathway to developing fault-tolerant quantum computers, which are pivotal for practical applications of quantum computing technologies.

In her explorations, Professor Nemoto has meticulously defined the architecture of quantum computers, outlining the diverse layers that comprise these innovative systems. Her quantitative evaluations of operational performance within integrated quantum systems serve as a cornerstone for what is termed “quantum middleware”—software solutions designed to enhance the efficiency and functionality of quantum operations. This theoretical groundwork not just strengthens the molecular fabric of quantum technology but also accelerates the nascent research necessary for moving from theory to practical applications.

With a dedicated role as the Director of the OIST Center for Quantum Technology, established in 2022, Professor Nemoto is at the helm of Japan’s efforts to fortify its status as a global leader in quantum technology. This center serves not only to advance research and development but also as a national hub connecting quantum researchers and fostering an environment ripe for collaboration and innovation. In her dual capacity as an educator and mentor, Professor Nemoto is deeply engaged in nurturing the next generation of leaders in quantum computing. This endeavor is evident through her active contributions to various educational initiatives, including her participation in the Quantum Academy for Science and Technology consortium.

Professor Nemoto’s accolades extend internationally, solidifying her position as a thought leader in the global quantum community. She holds Fellowships in esteemed organizations such as the American Physical Society and the British Physical Society. Additionally, her outstanding work in the field of quantum technology was recognized in 2022 when she was awarded the Officer of the National Order of Merit by the French Republic. These accolades are testament not only to her individual contributions but also to the collaborative efforts in the scientific community that push the boundaries of what is possible in quantum science.

In response to this latest award, Professor Nemoto expressed her heartfelt gratitude, stating, “I am truly honored that the outcomes of my fundamental research in quantum science have been recognized.” She reflected on the collaborative nature of research and the crucial support she has received over the years, underscoring that advancements in quantum technologies are a collective triumph and an essential component of scientific progress. Her awareness of the collaborative ecosystem in scientific inquiry underscores the vital role that teamwork plays in achieving great strides in research.

Professor Nemoto further emphasized the transformative era that quantum technology is ushering in, where scientific understanding and technological advancements are symbiotically linked. The ongoing exploration into quantum science not only enhances technological capabilities but also provides deeper insights into the quantum realm itself, effectively creating a feedback loop of knowledge that propels both fields forward. The future promises remarkable developments, and Professor Nemoto remains committed to her role in fostering progression along this spectacularly intricate path.

While the field of quantum computing is still in its evolving stages, experts suggest that its potential to revolutionize industries ranging from cryptography to optimization algorithms cannot be overstated. As Professor Nemoto articulates, the foundational research nurtured today will yield the seeds for monumental growth in the years to come. Her analogy of carefully sowing and nurturing seeds resonates in the scientific community, emphasizing the patient and persistent effort needed to cultivate groundbreaking ideas into tangible advancements.

The visionary endeavors led by Professor Nemoto not only embody the principles of inquiry and innovation but also reflect a broader commitment to bridging gaps in knowledge and technology on an international scale. OIST, under her leadership, actively promotes open innovation, establishing itself as a connecting thread among globally recognized quantum researchers, thereby amplifying Japan’s influence in the international arena of scientific research.

As news of Professor Nemoto’s recognition spreads, the implications of her work and the future of quantum computing will undoubtedly continue to inspire a multitude of researchers, scholars, and students alike across the globe. Her journey underscores a fundamental truth—great discoveries are the result of unyielding curiosity and an unwavering commitment to pushing the boundaries of our understanding, and the field of quantum technology stands at the cusp of a new frontier, one that promises exciting possibilities for generations to come.

Professor Kae Nemoto’s award is a reflection of her extraordinary contributions and a celebration of the transformative potential of quantum computing. As this field continues to evolve and expand, the collaboration and dedication of researchers like Professor Nemoto will be instrumental in shaping a future that capitalizes on the full promise of quantum science and technology.

Subject of Research: Quantum Computer Architecture Theory
Article Title: Recognition for Groundbreaking Research in Quantum Computing
News Publication Date: April 8, 2025
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