Developing Error Correction for Quantum Computers Is Becoming Increasingly Complex, But There’s Still Hope

Some experts argue that the efforts invested in quantum computing aren’t yielding significant results. Israeli mathematician Gil Kalai, a professor at Yale University, is one of the most critical members of the scientific community regarding quantum computers. He believes that the increasing number of states of quantum systems and their complexity will cause them to behave like classical computers, eventually diminishing the superiority of quantum computers.

However, despite the lack of unanimous support from the scientific community, it’s important to acknowledge the efforts and notable advances many research groups are making. Some of these groups are integrated into the structures of companies with substantial resources, like IBM, Google, or Intel. Moreover, these companies argue that the anticipated error correction in quantum computers will enable them to address a much wider range of problems than current prototypes.

IBM’s roadmap indicates that the company anticipates having error-correction capability by 2026. Although it may not materialize precisely in that year, it’s evident from its commitment that the standard for quantum computers will likely rise before the end of this decade. If error correction becomes a reality, the prototype quantum computers we currently have will transcend their prototype status, enabling the tackling of truly significant problems.

MIT-Led Study Casts Doubt on Error Mitigation

The main challenge for quantum computers in error correction is dealing with noise, which refers to disturbances that can change the internal state of the qubits and lead to computational errors. Many research groups working on quantum computers are focusing on monitoring the operations of the qubits in real time to identify and correct errors. However, this approach is extremely difficult to implement in practice.

However, experts are exploring an alternative approach known as “error mitigation.” Broadly speaking, this method allows the qubits to carry out their calculations even in the presence of errors and only infers the correct result at the end of the process. Error mitigation has shown promising results, but so far, no research group or company has developed a complete error correction technology for quantum computers. It’s a complex task.

A recent study published in Nature Physics, led by researchers at Massachusetts Institute of Technology, or MIT, and involving other universities, has revealed that quantum error mitigation techniques become less effective as the complexity of the quantum machine increases. The study suggests that as the number of qubits in the prototype quantum computer grows, the likelihood of higher error rates also increases. Therefore, the researchers argue that error mitigation may not be a viable long-term solution for implementing a complete error correction strategy.

The MIT researchers have identified the least effective mitigation techniques for dealing with noise, intending to guide other physicists and quantum engineers in implementing more effective alternative solutions. In fact, they’ve confirmed that in their future studies, they plan to shift their focus toward developing possible solutions to address the shortcomings of error mitigation strategies. Some scientists are already making progress in this area, offering promising results that suggest a hopeful future for quantum computers.

This article was written by Juan Carlos López and originally published in Spanish on Xataka.

Image | IBM

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