Breakthrough method could shield quantum information from noise, lead to stable quantum computers

Scientists from the University of the Witwatersrand in Johannesburg, South Africa, in partnership with Huzhou University in China, have found a method to shield quantum information from environmental interference—paving the way for more dependable future technologies.

In a study published in Nature Communications, researchers demonstrated that certain quantum states can retain crucial information even when exposed to environmental disturbances.

“Our research shows that topology offers a powerful way to encode information that resists noise,” explained Professor Andrew Forbes from the Wits School of Physics.

Quantum entanglement—an invisible link between particles that allows instantaneous communication across distances—is a fundamental concept in quantum science and technology. Despite its popularity, Albert Einstein famously dismissed it as “spooky action at a distance.”

However, entangled quantum states are extremely delicate and can easily collapse due to interference from external factors like background light, noisy detectors, photon loss, or general environmental noise—common challenges in real-world quantum systems.

Many techniques have been proposed to protect entanglement, but with limited success. Now, the Wits team has taken a different approach—allowing the entanglement itself to remain delicate, while instead focusing on preserving the quantum information it carries.

“We’re precisely shaping the quantum wave function—the mathematical framework that describes all possible states of a quantum system—to ensure the information remains intact, even when the entangled connections begin to deteriorate,” said Forbes.

The researchers found that by designing quantum states with specific topological characteristics, they could safeguard quantum information even when the entanglement between particles starts to degrade.

“What we’ve discovered is that topology provides a highly effective method for encoding information in noisy environments. It offers a broad encoding range that remains completely unaffected by noise—as long as some level of entanglement is preserved,” said Professor Andrew Forbes.

Professor Robert de Mello Koch adds that adjusting the topology of quantum waveforms acts like a form of "digitizing quantum information," thanks to the discrete nature of topological features, which can only take on whole number values, such as –2, –1, 1, or 2.

“Because discrete signals only register changes when the noise is strong enough to flip them from one state to another, they’re naturally more resistant to interference,” Koch explains.

The researchers suggest that just as digital technology revolutionized classical computing and communication, digital quantum signals could make quantum systems more reliable under real-world conditions—eliminating the need for complex noise-canceling techniques.

“This advancement could help mitigate noise in quantum computers and global quantum networks, paving the way for the next generation of quantum technology. It also holds promise for developing sophisticated medical imaging tools and more advanced AI systems powered by entanglement,” Forbes said.