Researchers from IBM and the University of Chicago have succeeded in using a quantum computer to perform calculations that are realistically difficult to process using classical simulation methods, while simultaneously verifying the accuracy of the results. It is noteworthy for demonstrating the possibility of reliable quantum computation, going beyond simply solving more difficult problems.

IBM and the University of Chicago disclosed the results of the experiment on the 31st through a paper titled 'Sampling hard circuits with verifiably high fidelity'.

The research team announced that they achieved the largest scale logic quantum computing experiment conducted to date by utilizing a newly configured quantum circuit with an encoding method.

The key to this experiment lies in overcoming the limitations of the Random Circuit Sampling (RCS) method previously used for quantum supremacy verification.

There was a problem where, as the scale of the problem increased, it became virtually impossible to verify the calculation results using classical methods.

The research team demonstrated that it is possible to detect errors in the calculation process and verify results by introducing a structured alternative method while maintaining the same difficulty criteria as RCS.

"We have developed a technique to evaluate how accurately quantum states that are classically difficult to compute are realized, even in noisy environments," said Bill Fefferman, an associate professor at the University of Chicago. "This experiment raises confidence that quantum computers are solving computationally difficult problems."

The research team performed 2,415 logic 2-qubit operations and 468 logic T gates in a way that protected 70 logic qubits from errors.

The logical error rate was only one-tenth of the physical error rate, and the IBM quantum computer completed the entire calculation in less than 15 minutes.

On the other hand, several modern classic simulation methods have been shown to require excessively long execution times for the same tasks.
Jay Gambetta, IBM Fellow and General Manager of IBM Research, stated, “We have demonstrated quantum computations that are practically impossible for classical computers to achieve, and presented the statistical reliability of how faithfully those computations were executed,” adding, “This achievement provides a new foundation for trusting quantum computers.”

IBM also released the results of this experiment on the Quantum Advantage Tracker.

In addition, IBM Quantum ecosystem partners such as Algorithmiq and Qedma also announced additional research results regarding trusted quantum supremacy on this day.