New research could lead to error-free quantum calculations

29 Sep 2023

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The research claimed to hit 99.9pc accuracy in certain quantum operations in a way that can be scaled up, which could help reduce errors.

Researchers from Massachusetts Institute of Technology (MIT) claim to have found a new way to dramatically increase the accuracy of quantum computers, which could increase the rate of error correction on these advanced machines.

The team claim their new method led to near 100pc accuracy and showed potential in being scaled up in the future.

It is believed that quantum computers will eventually be able to solve problems that are far too advanced for modern supercomputers, which could lead to endless breakthroughs for humanity.

But the path to get there isn’t easy, as current quantum systems are prone to calculation errors, which becomes a bigger problem the larger the computer is. Researchers at MIT said quantum versions of error correction codes need to be able to account for computational errors faster than they occur, but this isn’t currently possible at a viable scale.

To overcome this roadblock, these MIT researchers said they demonstrated a new form of qubit – quantum bit – architecture that can perform operations at a much greater accuracy than previous examples.

The researchers said this new accuracy was achieved by using a less common type of superconducting qubit known as fluxonium, which can have a much longer lifespan than normal superconducting qubits.

Reducing noise

Performing computations on a quantum computer involves creating a quantum circuit, which is a series of operations called quantum gates. These gates change the quantum states of certain qubits in order to perform calculations. But these gates are prone to errors.

To reduce the level of errors that these calculations are prone to, the researchers said they used a special coupling element between two fluxonium qubits that enabled them to perform these operations – or gates – while suppressing a type of background interaction that is known to introduce calculation errors.

In their study, the researchers said they created two-qubit gates that exceeded 99.9pc accuracy and single-qubit gates with 99.99pc accuracy. The researchers also said this architecture was implemented on a chip with a fabrication process that can be extended.

“We showed a highly promising two-qubit system and laid out its many advantages for scaling,” said PhD candidate and lead author of the study Leon Ding. “Our next step is to increase the number of qubits.”

The researchers said this high rate of gate accuracy is well above the threshold needed for common error correcting codes to work, which could lead to effective error detection in larger-scale systems.

Many researchers are working to bring us closer to fault-free quantum computers. Earlier this year, quantum computing company Quantiniuum claimed it was able to accurately simulate a hydrogen molecule by using an error-detecting code.

In March 2022, MIT researchers claimed they had developed a technique to make quantum circuits more resilient to noise, which could help boost performance and reduce errors in quantum computers.

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Leigh Mc Gowran is a journalist with Silicon Republic

editorial@siliconrepublic.com