Researchers at the University of Rochester and Rochester Institute of Technology recently connected their campuses with an experimental quantum communications network using two optical fibers. In a new paper published in Optica Quantum, scientists describe the Rochester Quantum Network (RoQNET), which uses single photons to transmit information about 11 miles along fiber-optic lines at room temperature using optical wavelengths.

Quantum communications networks have the potential to massively improve the security with which information is transmitted, making messages impossible to clone or intercept without detection. Quantum communication works with quantum bits, or qubits, that can be physically created using atoms, superconductors, and even in defects in materials like diamond. However, photons—individual particles of light—are the best type of qubit for long distance quantum communications.

Photons are appealing for quantum communication in part because they could theoretically be transmitted over existing fiber-optic telecommunications lines that already crisscross the globe. In the future, many types of qubits will likely be utilized because qubit sources, like quantum dots or trapped ions, each have their own advantages for specific applications in quantum computing or different types of quantum sensing.