The optical fibers connecting two quantum research labs at the University of Michigan mark the first piece of a local quantum network and remote user test facility
Researchers and students can now remotely run new kinds of quantum experiments on campus at the University of Michigan, thanks to the establishment of a quantum testbed that links two labs with optical fibers.
The ultimate aim is to provide broader access to the tools needed for quantum technology development and build a robust educational resource based on the experimental data.
Quantum researchers, who explore the behavior of particles and light at scales smaller than a single atom, often have to deal in theory because they lack the facilities and resources to fully test their predictions. For instance, entanglement-a phenomenon in which two particles become linked so that measuring one instantly changes the state of the other-may be tested over distances of miles at just a handful of facilities with restricted, in-person access.
Lacking travel resources, many quantum researchers work within a single lab. This makes it hard to take advantage of entangled light that may be transferred and measured over long distances.
Now, an optical fiber link has been installed between the labs of Zheshen Zhang and Parag Deotare, two associate professors of electrical and computer engineering. The link allows them to use light to transfer encrypted or entangled information between their facilities in the Electrical Engineering and Computer Science Building on North Campus and the Randall Laboratory on Central Campus, about three miles apart.
The transfer of information encoded in light through glass fibers isn't new-you may even be using fiber internet to read this story. But the transfer of quantum information (qubits) over these fibers could revolutionize communication, computing, scientific discovery and more with its speed and privacy protection.
"You can think about this link as an extension of the current internet, with telecommunication fibers transmitting optical signals, but now we have the new capability to distribute quantum states of light in addition to classical states of light," Zhang said.
The research team has already run some basic experiments on the testbed and demonstrated that they can transport entangled light across the link. The team has also developed a set of interactive demonstrations that allow researchers and students to learn quantum theory and then see how the theory plays out in real life with data prerecorded on the testbed during actual experiments. Anyone can try them at qreal.cloud.
Because specialized hardware is required to generate quantum states of light or perform other quantum experiments, access to quantum science and technology development has been restricted to people in very high-resource settings. This has created a barrier for the broader community-at universities or industry partners that lack these facilities-to apply their talents to advancing quantum technology.
Zhang and Deotare aim to dismantle that obstacle for researchers.
"If we can create a portal that allows external users to remotely access the testbed resources, that greatly facilitates technology advancement and technology transfer," Zhang said.
The collaboration between Zhang and Deotare is just the beginning. They aim to connect additional quantum research facilities at the University of Michigan, at other local universities and in local industry, creating a larger-scale quantum network for all types of quantum experimentation.
"Part of this project is also education and workforce development," said Deotare, who is also an associate professor of physics. "The distributed network that we're creating would serve as excellent infrastructure for industry folks to visit and spend a couple of weeks trying to understand quantum experiments at a distributed network level and getting experience with an actual system."
A local fiber infrastructure already exists in many places across Ann Arbor, facilitating the connections by Zhang and Deotare. They are collaborating with Merit Network, a local service provider that oversees telecommunication fiber links to local community colleges and industries, to expand their testbed network infrastructure.
Between the two labs, the network already has access to equipment that can create entanglement and detect it. They plan to incorporate additional labs that use a variety of physical quantum platforms, including neutral atoms, 2D materials, trapped ions and superconducting qubits-many of which already exist at Michigan.
"Our testbed would serve as the backbone of interconnecting quantum systems, and, in turn, advance the development of different quantum systems," Zhang said. "Our vision is that the testbed becomes a local engine for innovation and workforce development."
Ph.D. students Alexander McFarland, Visuttha Manthamkarn and Kailu Zhou, all in electrical and computer engineering, were instrumental in setting up the connection and remote testing capability. The research and development of the testbed has been funded by the U-M Office of the Vice President for Research. The educational aspects of the project have been supported by the National Science Foundation.
