The University of Arizona Center for Quantum Networks is leading a new international research and development partnership that will investigate technologies that will form the foundations of a quantum internet.

The partnership, with research centers in the Republic of Ireland and Northern Ireland, was made possible by a combined investment of $3 million from the National Science Foundation, Science Foundation Ireland and the Northern Ireland Department for the Economy.

Dubbed CoQREATE, which stands for Convergent Quantum Research Alliance in Telecommunications, the transatlantic partnership will focus on developing technology that will provide connectivity between quantum computers over short and long distances.

Quantum computers are being rapidly developed, with the first devices already commercially available. Unlike conventional computers, which use electrical charges inside semiconductors – commonly referred to as "zeros and ones" – quantum computers harness quantum mechanical effects known as quantum bits, or "qubits," which make them orders of magnitude faster and more capable of certain enormously complex calculations.

"Because they compute using qubits, networking quantum computers will require fundamentally new communications infrastructure that is capable to transmitting packets of qubits reliably and fast over long distances, while relying on the classical internet for some of their functions," said Saikat Guha, a professor in the UArizona James C. Wyant College of Optical Sciences and director of the Center for Quantum Networks, a National Science Foundation Engineering Research Center based at the university.

Guha said the quantum internet will not replace the existing "classical" internet. Rather, the two will coexist and cooperate to allow for many new applications that are not possible today. The quantum internet will need a robust classical communications backbone to function, thereby increasing the burden on the classical network, and some of the underlying technologies of the existing internet will need to be upgraded to be compatible with quantum communications.

"CoQREATE is an effort to figure out how these two technologies can work together," Guha said.

The partnership brings together four large research centers: the Center for Quantum Networks; Science Foundation Ireland's Research Centre for Future Networks and Communications; the Irish Photonic Integration Centre, a center of excellence for research and training in photonics; and Quantum Technology at Queen's University in Northern Ireland. The project provides funding for at least 10 research positions.

Quantum computers have the potential to perform many computing tasks faster than classical computers, in some cases solving problems that are impossible for classical computers to solve with today's computing power. Quantum computing takes advantage of two quantum mechanical phenomena:

• superposition – the ability of a physical system's state to be two opposite things at the same time, like in the famous Schrodinger's cat thought experiment, in which the cat is in a superposition of being both dead and alive
• entanglement – a coordination of the quantum states of two or more particles serving as computational bits that is stronger than what is possible in the realms of classical physics

The quantum internet will surpass the capabilities of today's internet because of the unique advantages of entanglement, which will improve the internet in at least two important ways, Guha said.

"First, it will enable physics-based communications security and privacy guarantees in multi-party transactions that cannot be compromised by any amount of computational power," he said. "Second, it will create a global network of quantum computers, processors and sensors that are fundamentally more powerful than today's technology. This will bring unprecedented advances in distributed computing and powerful long-baseline telescope systems, and enable secure access to quantum computers for the public."

Linking computers together over a quantum internet will allow for quantum computing with even greater computational power compared to that of individual computers. The new internet will be a collection of repeaters, routers, switches and other elements that allow the distribution of entanglement over large distances: across cities, countries and, eventually, continents.

"In addition to the technology aspect, the CoQREATE partnership will include research on socio-technical convergence to bring a broader social perspective to the program," Guha said. "This research will focus on societal impacts of quantum internet-enabled technologies surrounding privacy and security, unintended implicit biases embedded in the technology, equitable access and education."