Scientists from the University of Chicago, the University of California, Berkeley, Argonne National Laboratory, and Lawrence Berkeley National Laboratory have developed a new molecular quantum bit that bridges the gap between light and magnetism, operating at the same frequency as existing telecommunications technology. This breakthrough, published in the latest issue of Science, provides a promising new platform for building scalable quantum technologies that can be seamlessly integrated with currently used fiber-optic networks.
In quantum technologies, light is commonly used to transmit and measure quantum states, while magnetic spins are key resources for quantum computing, sensing, and storage. This research cleverly combines quantum optics, which has advanced the development of lasers and quantum networks, with synthetic chemistry, which has demonstrated powerful capabilities in applications such as magnetic resonance imaging contrast agents, to create a molecular-scale functional unit that bridges these two fields.
The core component of this new molecular quantum bit is the rare earth element erbium. Due to its unique physical properties, erbium can maintain “clean” optical transitions while interacting strongly with magnetic fields, making it of great value in both classical optoelectronics and emerging quantum systems. The newly designed molecular structure allows information to be encoded in its magnetic spin state and read and manipulated using specific wavelengths of light—frequencies that are compatible with existing silicon-based photonic circuits and fiber-optic communication systems.
The research team demonstrates that these molecules act as a nanoscale bridge between the magnetic and optical worlds, allowing them to store quantum information in the molecules’ magnetic states and access it using optical signals that are perfectly compatible with modern optical communication infrastructure.
Using spectroscopy and microwave techniques, the team verified that these erbium-based molecular quantum bits operate at frequencies compatible with silicon photonics, a core technology underlying modern telecommunications, high-performance computing, and advanced sensors. This high compatibility with established industry standards is expected to accelerate the development of quantum networks based on hybrid molecular-photonic architectures and facilitate the advancement of next-generation electronic devices.
The research also demonstrates that the behavior of quantum materials can be precisely designed and manipulated at the molecular scale through synthetic chemistry. This paves the way for the development of customized quantum systems for quantum networks, highly sensitive sensing, and next-generation computing.
Marking the centennial of quantum mechanics, this year’s Nobel Prize in Physics was awarded in quantum mechanics. This latest research demonstrates that quantum technology is taking a crucial step toward practical application. By achieving the synergy of light and magnetism through molecular engineering, this not only addresses the challenge of converting quantum information between different carriers but also opens up the possibility of directly connecting quantum systems with classical communication infrastructure. The true breakthrough lies in the unification of scalability and integrability.
In the future, these qubits are expected to become core nodes in building distributed quantum networks, driving the development of ultra-sensitive biosensors, chip-scale quantum processors, and globally secure quantum communications. This is both a triumph for materials science and a substantial step towards the era of large-scale quantum interconnection.
