IBM: No, Google Didn't Achieve Quantum Supremacy

In a research paper shared Monday, IBM contesting the a leaked Google paper pointing to a Google quantum computer having better performance than a classical supercomputer. The leaked documents said a task that'd take Google's quantum computer 3 minutes and 20 seconds would take a classical computer 10,000 years to finish with far less fidelity. IBM begs to differ. 

Quantum Supremacy Not Achieved?

A paper from Google’s quantum computing researchers leaked last month said Google’s quantum computer could achieve “quantum supremacy,” which is solving a certain task that wouldn’t be solvable by classical computers within a reasonable timeframe. The leaked paper seemed to present that, demonstrating a task run by a quantum computer that would take a classical supercomputer 10,000 years. 

But now IBM is contesting the claim. Its blog post and research paper say it was able to complete the same task in less than 2.5 days on a classical system. IBM argued that Google didn’t tap into the full potential of a supercomputer to solve the task with classical algorithms. 

But it's important to note that since the paper on Google's quantum computer was a leak, Google has never actually officially claimed that it achieved quantum supremacy. 

Regardless, IBM said that the quantum solution used in the leaked research used a large amount of RAM but didn’t take advantage of disk storage. This led to the conclusion that it would be virtually  impossible to run the simulation (in RAM) on a classical supercomputer.

IBM said it ran the same simulation on large amounts of RAM as well as on even greater amounts of disk storage. IBM also employed several other performance-enhancing techniques to speed up its classical computing operations and make them more efficient.

To make a true comparison to a quantum computer, you have to also compare it to the best supercomputers, and that includes highly-optimized classical algorithms. According to IBM, Google didn’t go to these lengths to optimize the classical system and its algorithms.

“Building quantum systems is a feat of science and engineering, and benchmarking them is a formidable challenge. Google’s experiment is an excellent demonstration of the progress in superconducting-based quantum computing, showing state-of-the-art gate fidelities on a 53-qubit device, but it should not be viewed as proof that quantum computers are 'supreme' over classical computers," IBM's blog post says.

IBM added that the term “quantum supremacy” has been misused in general, because quantum computers will never actually reign supreme over classical computers. It’s far more likely they will work in concert together, Big Blue argued. 

This is also why IBM started using the term “quantum advantage,” which refers to the fact that quantum computers can run certain algorithms significantly faster than classical systems can, even though the complete solution may require classical computers to solve certain parts of the problem and quantum computers to solve others.

IBM said quantum computers have inspired a new generation of scientists, physicists and engineers to work on new types of information technology problems. IBM has also recently announced a 53-qubit quantum computer, along with 80 partnerships with institutions and commercial organizations.