As powerful as quantum computers may theoretically one day be, they are currently so prone to error that their ultimate utility is often questioned. Now, however, IBM argues that quantum computing may be entering a new era of utility sooner than expected, with its 127-qubit Eagle quantum computer potentially delivering accurate results on useful problems beyond what even today’s supercomputers can tackle.

Quantum computers can in theory find answers to problems that classical computers would take eons to solve. The more components, known as quantum bits or qubits, that a quantum computer has linked together, the more basic computations, known as quantum gates, it can perform, in an exponential fashion.

“These methods can be applied to other, more general circuits.”
—Kristan Temme, IBM

The key problem that quantum computers face is how notoriously vulnerable they are to disruption from the slightest disturbance. Present-day state-of-the-art quantum computers typically suffer roughly one error every 1,000 operations, and many practical applications demand error rates lower by a billionfold or more.

Scientists hope to one day build so-called fault-tolerant quantum computers, which can possess many redundant qubits. This way, even if a few qubits fail, quantum error-correction techniques can help quantum computers detect and account for these mistakes.

Quantum Utility: The IBM Quantum and UC Berkeley experiment charts a path to useful quantum computing.IBM/www.youtube.com

However, existing quantum computers are so-called noisy intermediate-scale quantum (NISQ) platforms. This means they are too error ridden and possess too few qubits to successfully run quantum error-correction techniques.

Despite the current early nature of quantum computing, previous experiments by Google and others claimed that quantum computers may have entered the era of “quantum advantage,“ “quantum primacy,“ or “quantum supremacy” over typical computers. Critics in turn have argued that such tests showed only that quantum computers were able to outperform classical machines on contrived problems. As such, it remains hotly debated whether quantum computers are good enough to prove useful right now.

Now IBM reveals that its Eagle quantum processor can accurately simulate physics that regular computers find difficult to model past a certain level of complexity. Not only are these simulations of actual use to researchers, the company says, but the methods they developed could be applied to other kinds of algorithms running on quantum machines today.

In experiments, the researchers had IBM‘s quantum computer model the dynamics of the spins of electrons in a material to predict its properties, such as magnetization. This model is one that scientists understand well, making it easier for the researchers to validate the correctness of the quantum computer’s results.

“Importantly, our methods are not limited to this particular model,” says study coauthor Kristan Temme, a quantum physicist at IBM’s Thomas J. Watson Research Center, in Yorktown Heights, New York. “These methods can be applied to other, more general circuits.”

This chart shows the performance of quantum computer versus state-of-the-art classical approximation methods compared to the exact cla