News release

From: Springer Nature

A highly accurate 98-qubit computer

A 98-qubit quantum computer that operates at high accuracy and in a way that classical computers cannot reproduce is reported in Nature. The demonstration highlights the potential for the scalability of this type of quantum computer, although challenges remain to see if this technology can be applied to even larger quantum systems.

Quantum computers require large numbers of quantum bits (qubits, a unit of information) to improve upon traditional computing power. However, current iterations of the technology have struggled to scale-up the number of qubits in use whilst maintaining accuracy and performance.

Anthony Ransford and colleagues report a new 98-qubit trapped-ion quantum processor named Helios. In a trapped-ion processor, charged atoms (in this case barium ions) are suspended in an electromagnetic field to act as qubits and perform logical operations known as gates. Although quantum computers larger than 98 qubits exist, no other trapped-ion computer has reached this size before. Quantum computers with trapped ions have been shown to have higher accuracy than other platforms, with the authors reporting an average fidelity of 99.921% for two-qubit gates. Benchmark tests indicated that Helios outperformed classical computing methods in both computation speed and energy efficiency. Other measurements of performance improvements in comparison to previous iterations included a reduction in gate errors, smaller memory errors, and reduced circuit times.

The authors note that further testing is needed to precisely understand the power and limitations of the Helios system. Crystal Noel, the author of an accompanying News & Views article, states that tackling ongoing engineering challenges of the system “will be essential for trapped-ion architectures to reach the next frontier of large-scale quantum computation.”