A topological alternative For the team at Nokia Bell Labs, the solution lies in better qubits rather than bigger machines.
Specifically, rather than information encoded in individual elementary particles, the team is focused on qubits that hold this same information in the way matter is spatially oriented—what is known as a topological qubit.
This alternative approach uses electromagnetic fields to manipulate charges around a supercooled electron liquid, triggering the qubits to switch between topological states and locking them in place for far longer periods of time.
It is inherently more stable as a result, explains Eggleston. “We have these electrons, and they're sitting in a plane, in one state. If I move them around each other, they're now in a different state. But that’s really hard to accidentally do, it doesn’t happen randomly. And so that allows you to build a stable system that you can control.”
In fact, while existing qubits have a lifespan of milliseconds, for topological qubits this could be several days, he adds. “It’s incredibly stable. Many, many orders of magnitude more stable.”
Some of the science that underpins the topological qubit dates back decades. In 1998 Bell Labs scientists Daniel Tsui and Horst Störmer were awarded the Nobel Prize in Physics for their discovery six years earlier of a counterintuitive physical phenomenon, later dubbed the fractional quantum Hall (FQH) effect. FQH refers to how electrons manipulated under strong magnetic fields and at very low temperatures can create new states of matter. These states are being leveraged nearly 40 years later to form the basis of topological qubits.
But in so many other ways, the push toward a topological qubit has placed scientists firmly in unknown territory. “The development of the technology can be frustrating because nobody’s done this before,” admits Eggleston. “It’s completely open sky. We’re often ahead of the theorists.”
“Nobody's ever actually shown you can control the topological state and switch it on and off. And that's what we're wanting to demonstrate this year. That’s what the scientists in our lab are working on as we speak.” Michael Eggleston, Research Group Leader, Nokia Bell Labs
That’s why the Nokia Bell Labs team has often worked collaboratively with the competition to advance the field. Much of the early research saw them work closely with Microsoft, for example. But they’re also hoping that 2025 will mark the year that sets their research apart.
In the coming months, the team at Nokia Bell Labs hopes to demonstrate their ability to control the qubit for the first time, intentionally moving it between states to offer enhanced stability and resilience against errors.
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