Microsoft says its researchers have found evidence of an exotic phenomenon that is key to its plans to build general-purpose quantum computers.
The phenomenon known as the Majorana null mode is said to pave the way for topological quantum computing – the technological approach favored by Microsoft Azure Quantum Program.
Quantum computing is a strange concept in itself: unlike the rigid one-or-zero world of classical computing, quantum computing juggles quantum bits, or qubits, which can represent ones and zeros at the same time until the results are read out.
Scientists say that the quantum approach can solve certain types of problems – for example, network optimization or simulations of molecular interactions – much faster than the classical approach. Microsoft Azure, Amazon Web Services, and other cloud-based services are already using hybrid systems to bring some of the benefits of the quantum approach to applications ranging from drug development to traffic management.
At the same time, Microsoft and other companies are trying to develop the hardware and software for “full-stack” quantum computing systems that can take on a much broader range of applications. Microsoft has chosen a particularly exotic technological strategy that involves induction Quantum states on topological superconducting wires. To keep these quantum states stable, the wires would host Majorana null modes localized at each end.
Majorana null modes have been a topic of theoretical interest since 1937, but remained strictly in the field of theory for decades. In 2018, a team of researchers reported that they created the phenomenon just to do that withdraw their claims three years later. have other claims encountered controversy even, cast doubt on the prospects for topological quantum computing.
Last year, an analysis of data from Azure Quantum’s experimental quantum devices found signatures suggesting that Majorana null modes were present at both ends of a precisely tuned nanowire. Other signatures in the electrical conductivity data indicated the opening and closing of what is known as a topological gap — another telltale sign that points to a successful detection.
“It was suddenly wow,” said Roman Lutchkin, a Microsoft partner research manager with expertise in quantum simulation, in a Microsoft report on Majorana research. “We looked at the data and that was it.”
Zulfi Alam, a corporate vice president leading Microsoft’s quantum computing effort, said the hardware team invited an outside expert council to review and validate the findings.
Even when the results are validated, it will take a lot more research to create topological qubits and assemble a quantum computer ready for prime time. But at least Microsoft’s researchers will be confident they’re on the right track.
“What’s amazing is that humans have been able to engineer a system to demonstrate one of the most exotic pieces of physics in the universe,” said Microsoft engineer Krysta Svore, who leads the company’s quantum software development program. “And we expect to capitalize on that to do the almost unthinkable — to work toward a fault-tolerant quantum machine that enables computation at a whole new level, closer to how nature works.”
The researchers discussed their findings this month during a meeting hosted by Microsoft Station Q in Santa Barbara, California. For more information, see latest edition of Microsoft’s Innovation Stories and Today’s Microsoft Research Blog post.