Google claims new milestone in detecting quantum computer errors

27 Feb 2023

Image: © Bartek Wróblewski/

The Google researchers claim they were able to detect more errors by increasing the number of qubits, which could help develop larger quantum computers that are ‘fault tolerant’.

Google researchers claim to have hit a new milestone in creating useful quantum computers by reducing the number of errors generated.

Quantum computers are expected to shake up various sectors when – or if – they become a reality. These powerful machines are able to handle complex calculations that would take thousands of years for a classic computer to solve.

However, one key issue with these machines is that they currently have errors in their quantum bits – or qubits – due to how sensitive these components are.

For example, imperfect control signals, interference from the environment and unwanted interactions between qubits can lead to “noise” that causes errors in quantum computer calculations.

The risk of errors grows as more qubits are added to a quantum computer, posing a challenge in creating more powerful machines. However, researchers at Google Quantum AI claim to have reduced the error rate while increasing the number of qubits.

In a study published in the scientific journal Nature, the team claim they were able to improve the rate of quantum error correction.

This process involves encoding information across various physical qubits into a “logical qubit”. The research team said this process allows more errors to be detected and overcome.

The researchers made a logical qubit that was composed of 49 physical qubits and claimed this had a better error detection rate than another logical qubit made of 17 quantum qubits. This result suggests that it is possible to scale up the rate of error detection with more qubits.

The Google team said the projections rely on “simplified models” and will need to be tested on larger code sizes for longer durations.

“This work demonstrates the first step in that process, suppressing logical errors by scaling a quantum error-correcting code – the foundation of a fault-tolerant quantum computer,” the team said.

Google and Alphabet CEO Sundar Pichai said the research is a “big step forward” in the company’s goal of making a large-scale quantum computer.

“Someday, we believe quantum computers will be used to identify molecules for new medicines, create fertiliser using less energy, design more efficient sustainable technologies from batteries to nuclear fusion reactors, and produce physics research that will lead to advances we can’t yet imagine,” Pichai said in a blog post.

New quantum breakthroughs are being reported by scientists around the world. Earlier this month, UK researchers claimed they solved a major challenge in building more powerful quantum computers, through a method that allows microchips to be slotted together like jigsaw pieces.

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Leigh Mc Gowran is a journalist with Silicon Republic