Google Claims Latest Quantum Experiment Will Take Decades on Classic Computers

Insider Summary

• Google scientists report in a new study that they completed a computational task on a quantum computer that would have taken a classical supercomputer 47 years to complete.
• Its task is the calculation of random circuit sampling.
• The experiment was carried out on the latest version of the Sycamore processor which has been upgraded to 70 qubits.
• Image: Google Quantum AI

Staking another claim of quantum superiority, Google scientists report that they completed a computational task on a quantum computer that would have taken a classical supercomputer 47 years to complete, Telegraph report.

Google scientists published their findings at ArXiv pre-press server. Scientists often use servers to distribute findings before seeking official peer review.

The team uses the latest version of Google’s quantum computer. In 2019, a 53-qubit machine, named Sycamore, was used in one of the first attacks on the quantum supremacy milestone. Quantum supremacy is the theoretical point at which quantum computers perform tasks far beyond the capabilities of classical computers or supercomputers.

In this task, the scientists used the latest version of the Sycamore, which features 70 qubits. You can think of qubits as the fundamental unit of quantum information, just as bits are the fundamental part of classical information.

These additional qubits mean that the new processor is 241 million times more powerful than previous versions, The Telegraph reports, although other factors, such as coherence time, can impact quantum computer performance.

The researchers note this experiment was designed to answer questions around this classical vs. quantum competition.

They write: “This intensifying quantum-classical competition motivates two questions: are there well-defined boundaries for the region where exponentially enormous Hilbert space is, in fact, affected by noise?
quantum processor? More importantly, can we create observable experiments that directly investigate this
limitation?”

In the experiment, the scientists performed a random circuit sampling task. In quantum computing, this involves testing the performance of a quantum computer by running random circuits and analyzing the resulting output to evaluate its ability and efficiency in solving complex problems.

According to The Telegraph, researchers compared their performance with Frontier, the world’s leading supercomputer, adding that it took 6.18 seconds to match calculations from Google’s 53-qubit computer from 2019. In comparison, it took 47.2 years to match the latest. .

The researchers also claim that this also beats a recent demonstration from a Chinese lab, one of the latest research teams to declare quantum supremacy.

The researchers report in the paper: “After estimating the computational resources required and the achievable fidelity bound to better classical methods, we conclude that our demonstration firmly falls within the non-classical quantum computing regime.”

According to The Telegraph, the experiment has received praise in the research community, although doubts remain about the practicality of the experiment. The practicality of the quantum computing task is one of the major criticisms of previous experiments on quantum superiority. For example, most people don’t have an urgent need for boson sampling or random circuit sampling, but do need access to cheaper drugs.

Steve Brierley, chief executive of Cambridge-based quantum company Riverlane, told The Telegraph: “This is an important milestone. The debate about whether we have achieved, or can actually achieve, quantum supremacy has now been resolved.”

Sebastian Weidt, chief executive of Brighton-based startup Universal Quantum, told the paper that quantum computers should lead to practical functions.

He said: “This is a very good demonstration of quantum superiority. Despite a great achievement academically, the algorithm used doesn’t really have any practical application in the real world. We really have to take advantage of quantum computing – an era where quantum computers with thousands of qubits are really starting to provide value to society in ways that classical computers never could.”

It is hoped that these more esoteric experiments will eventually lead to tools and practices that build the foundation for more practical calculations.