Quantum technology company Xanadu demonstrated quantum computational advantage using its Borealis photonic quantum computer. Borealis features 216 squeezed-state qubits, and it was demonstrated to outperform classical supercomputers in the performance of a specific task.

Xanadu has made the computer and its capabilities available to the public through Xanadu Cloud, the company’s photonic quantum computing platform, as well as through Amazon Bracket.

According to the company, the advancement makes Borealis the first photonic quantum computer offering full programmability of all its gates to demonstrate quantum computational advantage. It also marks the first time that a machine capable of quantum advantage is available to the public in the cloud.

In 2020, a team of physicists in China claimed that it had demonstrated quantum advantage using a light-driven quantum computer, Jiuzhang, capable of performing a computation that would take a classic supercomputer an estimated 600 million years to resolve. The team’s photonic quantum computer ultimately took several minutes to complete the boson sampling problem — a computation originally devised in 2011.

The 2020 demonstration and result followed Google’s 2019 announcement that its device, Sycamore, was the first to achieve a clear quantum advantage. Where chip-based superconducting circuits powered Sycamore, however, the Hefei, China-based team relied on photons delivered by a pump laser.

Xanadu’s Borealis synthesizes the squeezed-state qubits, which are entangled in three dimensions according to the user’s specified program. Borealis generates samples from this state at a rate exceeding the capabilities of any exiting classical supercomputer.

Borealis generated a sample in 36 µs. Using direct simulation, the world’s fastest supercomputer would take approximately 9000 years to generate a single such sample. This runtime advantage is more than 50 million times larger than that of earlier demonstrations using photonic systems.

“Among all photonic demonstrations of quantum computational advantage — photonic or otherwise —our machine uses the largest number of independent quantum systems: 216 squeezed modes injected into a 216-mode interferometer having three-dimensional connectivity, with up to 219 detected photons,” Xanadu said in a published paper. “Our demonstration is also more resistant to classical spoofing attacks than all previous photonic demonstrations, enabled by the high photon numbers and photon-number resolution implemented in the experiment.”

Borealis additionally features a quantum light source with adjustable brightness that emits trains of up to 288 squeezed-state qubits; a fully programmable loop-based interferometer, synthesizing a large, entangled state suitable for Gaussian Boson sampling; and the ability to dynamically program the gate parameters according to task.

In the last year, Xanadu has advanced collaborations with GlobalFoundries, Nvidia, Multiverse Computing, VTT Technical Research Centre of Finland, and Menten AI.

The research was published in Nature (www.doi.org/10.1038/s41586-022-04725-x).