Quantum Network Entangles Atoms for Record 10 Seconds.

Scientists at the University of Oxford have developed a quantum network using two different atoms—strontium and calcium—and set a record for a 10-second entanglement duration. This achievement opens the way to further extend entanglement times between atoms, which is of critical importance in the development of distributed quantum computing networks.

One of the most promising developments in quantum physics is the advancement of quantum computing technologies. use quantum bits () to store and process information. Unlike classical bits, which can only store the values 0 or 1, quantum bits can store multiple values between 0 and 1 and use them simultaneously for information processing.

Thus, qubits offer an exponential approach to processing large amounts of data; this can help tackle problems that would take today’s fastest supercomputers decades to solve. Quantum computers are therefore seen as the next frontier of computing. However, a critical component of scalable quantum computing is quantum entanglement.

Why is entanglement important?

Although a quantum bit can store multiple values simultaneously, its true benefit lies in being entangled with multiple other quantum bits, enabling the exploration of numerous correlations at once. This is only possible when one quantum bit is entangled with another, meaning that one determines the state of the other, even if they are not physically connected.

Entanglement also facilitates more dynamic interaction between qubits compared to the more naturally isolated standard units, by helping to create multi-qubit logic gates. It also enables quantum computers to handle more complex data structures in their computations and to solve some of the most difficult problems the world has ever seen.

Most importantly, entanglement enables quantum teleportation and allows different quantum processors to share information without actually sharing their quantum bits. This facilitates the construction of a distributed quantum infrastructure, helping to scale up quantum computing capabilities in a scalable manner.

How will Oxford’s research help?

In their experiments, researchers used strontium and calcium atoms, placing each in two different positions. As light linked the strontium atoms together, the team used local operations to spread quantum entanglement to the calcium atoms as well, creating a shared quantum state involving all four atoms.

The reason researchers use calcium in this setup is that it is less sensitive to magnetic noise compared to strontium and can be used to maintain its quantum state for a much longer time.

Different atom types offer different advantages and disadvantages for quantum applications,” said Oxford researcher Dougal Main in a press release. “Having multiple atom types in your quantum computer allows you to leverage the best features of each.

The researchers demonstrated the advantage of using different atoms by maintaining quantum entanglement for 10 seconds, in contrast to the few milliseconds achieved with the same cluster of atoms.

“This could make it useful for tasks in future quantum networks where several distant atoms need to share and protect the same quantum state,” said Gabriel Araneda, a University of Oxford researcher involved in this study, in a press release.

This could include quantum computing, more precise measurements performed at distant locations, and comparisons of different types of atomic clocks.

The researchers published their findings in the journal Physical Review Letters.