This Quantum Computing Company Just Unlocked a New AI Breakthrough

Globe and Mail

10 hours ago

Key Points
Rigetti has achieved a significant error rate reduction with a 36-qubit system.
This could pave the way for quantum computers with more qubits that can be used for AI.
There's still a long way to go, though -- and Rigetti's stock remains a speculative bet.
10 stocks we like better than Rigetti Computing ›
What are currently the two hottest technologies? Artificial intelligence (AI) deserves a spot at the top, for sure. There's a strong case for quantum computing taking second place. Not so coincidentally, these two technologies are joined at the hip in some ways.
When a key milestone is achieved in quantum computing, it can translate to a step forward for AI, too. That appears to be the case with a recent announcement from Rigetti Computing (NASDAQ: RGTI). This quantum computing company arguably just unlocked a new AI breakthrough.
Rigetti's breakthrough
On July 16, 2025, Rigetti Computing revealed that it had achieved 99.5% median 2-qubit gate fidelity with its modular 36-qubit quantum computing system. This reflected a halving of the company's best 2-qubit gate error rate with its 84-qubit Ankaa-3 system.
If all that sounds like techno-gobbledygook to you, you're not alone. Quantum computing is complicated, with jargon that can be confusing. Let's try to make sense of Rigetti's breakthrough.
First, qubits (short for "quantum bits") are similar to the binary bits 0 and 1 used in traditional computers. The big difference is that qubits can be 0, 1, or even both simultaneously. Quantum gates are the building blocks of quantum circuits. They're like logic gates used in traditional computers (such as AND, OR, and NOT) to perform operations.
What does it mean that Rigetti achieved 99.5% median 2-qubit gate fidelity? When 2 qubits interact in a "gate" operation, the result is correct 99.5% of the time, with an error rate of five in 1,000 operations. The fewer errors, the more useful a quantum computer is.
What does improved quantum gate error rates mean for AI?
Rigetti didn't mention AI at all in its announcement. However, its quantum computing breakthrough could have important ramifications for AI.
Error correction ranks as one of the biggest problems with quantum computers today. Too many errors make a quantum computer useless in practical applications. That's especially the case with AI, which requires multiple iterations and a high degree of precision in its under-the-hood processing.
However, lower error rates allow quantum computers to run longer and use more quantum gates before the accumulated errors cause major problems. It also paves the way for quantum computers with more qubits, which will be a must for training and deploying large-scale AI models.
We're seeing this with Rigetti already. The company made its breakthrough on a 36-qubit system. However, it plans to release a 100-plus-qubit system that will have 99.5% median 2-qubit gate fidelity before the end of this year. CEO Subodh Kulkarni stated, "By leveraging well-known techniques from the semiconductor industry, we've developed proprietary technology that we believe is critical to enable scaling to higher qubit count systems."
Now for a reality check: Five errors in 1,000 operations isn't nearly good enough. The error rate needs to fall to around one in a million for quantum computers to run useful applications. Some more complex applications will need error rates of one in a billion or better. However, Rigetti's achievement is nonetheless an important milestone in getting to these lower error rates.
Is Rigetti Computing stock a smart pick to buy now?
If you want to know how significant investors viewed Rigetti's breakthrough, just look at its stock chart. The quantum computing company's share price soared after its announcement earlier this month. Over the last three months, Rigetti stock is up close to 80%.
Is this quantum computing stock a smart pick to buy now? Not for risk-averse investors. Rigetti remains unprofitable. It also faces stiff competition from both large and small companies scrambling to develop quantum computers. There's no guarantee that Rigetti will be among the winners in quantum computing over the long run.
However, aggressive investors who are willing to take on considerable risk might find Rigetti appealing. It's a speculative stock, to be sure. But if Rigetti can continue to make the technological advances needed to build a practical, large-scale quantum computer, it's likely to be a huge winner over the next decade and beyond.
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