At the end of last year, a monumental breakthrough was announced with the first case of long-distance, high-fidelity quantum teleportation. This was quickly followed by the creation of a cryogenic quantum computer chip, and even a hologram using quantum entanglement just after that. You could say it has been a pretty big few months for the eventual goal of a quantum Internet, which could theoretically change everything when it comes to computing speed, privacy, and capabilities. 

However, new research suggests that could be even closer than we think. 

In a study conducted by two institutions in the Netherlands, scientists have created the first quantum network using quantum entanglement, successfully connecting three devices together. The research could lay the groundwork for creating a large-scale quantum network, a dream for many scientists in the field. Their work was published in the journal Science.

“This is the first time a network has been constructed from quantum processors,” said lead author Ronald Hanson in an interview with Inverse. “A single direct link between two processors has been shown on many platforms in the past decade, but no network had been achieved.” 

A quantum computer differs from a traditional computer in one fundamental way: traditional computers use binary to process information, using two states of either ‘on’ (1) or ‘off’ (0), whilst quantum computers add a new and more interesting state called superposition, which is both ‘on’ and ‘off’. Normal binary snippets of data are called bits, but quantum information is stored in qubits. Simply adding one extra state to the equation adds a wealth of new possibilities, with massively increased data flow. 

However, transmitting qubits is no easy feat. To do so, scientists must utilize the concept of quantum entanglement. Quantum entanglement, put simply, is a state of two or more particles in which observing the state of one provides information about the other – these particles are ‘entangled’. For example, if one particle was excited and in the 'on' state, the other would note this and behave in a similar way. This is useful in the rapid transmission of data because if two systems are entangled, data can be copied across and a network of systems can be created. 

In this study, a network of three nodes was set up, affectionately named Alice, Charlie and Bob. Using an extremely complex system of photon detectors and beam splitters within each node, the researchers were able to demonstrate remote entanglement between the three nodes, creating a quantum network. 

While entanglement between two devices has been demonstrated in the past, this marks the first case of three devices working as part of an entanglement network. The work marks an important milestone in that elusive dream of a quantum Internet – albeit, that likely won’t come soon. Quantum computing is still in its infancy and requires extreme amounts of power as well as a mess of wires that makes scaling an issue. It is, however, a landmark in what could soon be an Internet revolution.