Scientists have developed a new type of cryogenic chip capable of operating at temperatures so cold that it is approaching the theoretical limit of absolute zero.
This cryogenic system, called gooseberry, lays the groundwork for what could be a revolution in quantum computing, allowing a new generation of machines to perform calculations with thousands of qubits or more, while today’s more advanced devices only form dozens. .
“Currently, the world’s largest quantum computers run with only a few qubits,” explains quantum physicist David Reilly of the University of Sydney and Microsoft’s Quantum Laboratory.
“This small scale is due in part to the limits of the physical architecture that controls the qubits.”
This physical architecture is restricted due to the extreme conditions that qubits need to perform quantum mechanical calculations.
The Gooseberry chip (red) next to a qubit test chip (blue) and a resonator chip (purple). (Microsoft)
Unlike the binary bits of traditional computers, which have a value of 0 or 1, qubits occupy what is known as quantum superposition, an indefinite and immeasurable state that can effectively represent both 0 and 1 at the same time in the context of a mathematical operation.
This esoteric principle of quantum mechanics means that quantum computers can theoretically solve very complex mathematical problems to which classical computers would never be able to respond (or take years to try).
As with conventional technology, however, it is always better, and so far researchers have been limited in how many qubits they have been able to successfully deploy in quantum systems.
One reason is that qubits need extreme levels of cold to operate (in addition to other controlled conditions), and the electrical wiring used in current quantum computer systems inevitably produces small but sufficient heat levels that disrupt thermal requirements.
Scientists are looking for ways to fix it, but many quantum innovations so far have relied on the manufacture of bulky wiring equipment to keep temperatures stable to increase the number of qubits, but that solution has its own limits.
“Today’s machines create a beautiful range of cables to control signals; they look like an inverted golden spider’s nest or spider,” says Reilly.
“They’re beautiful, but basically impractical. It means we can’t scale the machines to make useful calculations. There’s a real input-output bottleneck.”
The solution to this bottleneck could be gooseberry: a cryogenic control chip that can operate at temperatures of “millikelvin” only a small fraction of a degree above absolute zero, as described in a new study .
This extreme thermal capacity means that it can sit in the super cold refrigerated environment with the qubits, relating to them and passing signals from the qubits to a secondary core that is outside in another extremely cold tank, immersed in helium. liquid.
In doing so, it removes the excess wiring and excess heat they generate, which means that contemporary qubit bottlenecks in quantum computing could soon be a thing of the past.
“The chip is the most complex electronic system that operates at this temperature,” Reilly told Digital Trends.
“This is the first time a mixed signal chip with 100,000 transistors has run at 0.1 kelvin, [the equivalent to] -459.49 degrees Fahrenheit or -273.05 degrees Celsius. “
Ultimately, the team hopes its system will be able to control thousands of qubits using the cryogenic chip, an increase of about 20 times what is possible today. In the future, the same type of approach could allow quantum computers to another level.
“Why don’t you start thinking about billions of qubits?” Reilly told the Australian Financial Review. “The more qubits we can control, the better.”
While it may be some time before we see this cryogenic breakthrough implemented outside the lab, there is no doubt that we are looking at a big step forward in quantum computing, experts say.
“This will be transformative in the coming years,” Andrew White, director of the ARC Center of Excellence for Quantum Engineering Systems, who did not participate in the study but oversees quantum research in Australia, told ABC News .
“Everyone [developing quantum computers] don’t use this chip, they will use something inspired by it “.
The findings are reported in Electronic nature.