Blueprint for Giant Quantum Computer Promises Mind-Blowing Power
Researchers unveil construction plans for a large-scale quantum computer that could be expanded to the size of a soccer field, harnessing the data-crunching processing power of thousands or even billions of ions.
Building a functioning large-scale quantum computer is the holy grail of physics. Such a computer, first theorized by Nobel prize-winning physicist Richard Feynman in 1982, would harness the strange and nearly magical properties of quantum particles to perform calculations several billions of times faster than any of our most powerful supercomputers.
Today, an international team of researchers based at the University of Sussex published what it describes as the first-ever open-source blueprint for constructing a large-scale quantum computer. While Google and other high-profile researchers have made impressive progress proving the viability of quantum computing, the Sussex team claims that its "nuts and bolts construction plan" is a major step toward a working prototype.
Winfried Hensinger leads the Ion Quantum Technology Group at the University of Sussex, which published the blueprint in Science Advances. In an interview with Seeker, Hensinger explained how quantum computers are "nothing like normal computers" because they take advantage of the strange quantum effects of atomic particles.
"In quantum physics, something can be in two different places at the same time," he said. "You can be sitting in the office right now and having a holiday in sunny California. In the real world, things like that don't happen, because quantum effects get destroyed when they interact with anything else, like light or the air around you. But when you isolate individual atoms, that actually happens."
In a normal computer, the smallest computational unit is a bit, which is represented as a 0 or 1. In a quantum computer, each quantum bit (or "qubit") is expressed by an individual charged particle, or ion. Thanks to the oddity of quantum physics, that ion can not only be a 0 or a 1, but both at the same time.
This "superpositioning" is one of the reasons why quantum computers can greatly magnify the processing power of a normal transistor-based system. The other is "entanglement," a physics trick in which two separate particles are linked in such a way that any action performed on one instantly occurs in the other.
Hensinger and his team have developed a modular design for a quantum computer that can be expanded to run complex algorithms in seconds that would take today's best computers millions of years to execute. The Sussex research group pioneered a new technology that uses electric fields to hold and transport individual ions or qubits from one module to another, like the video game "Pac-Man." The more "trapped ion" modules are interconnected, the greater the processing power.
Hensinger said his team's blueprint could expand to accommodate quantum computers with 5,000 to five billion qubits, enough computing power to replicate the quantum-level complexity of nature.
"For the first time, we asked the question: What kind of engineering would be involved to really build a large-scale quantum computer?" Hensinger said of the thought process behind the blueprint. "What components would you have to stick to it? What's the power consumption? What exactly would an individual quantum computer module look like?"
The Sussex team is now actively building a small-scale prototype of their modular quantum computer, which they hope to complete in two years. A full-scale version would take up an entire building and cost tens to hundreds of millions of dollars. Hensinger's research group is one of several labs that benefitted from a £247 million ($312 million) investment from the UK National Quantum Technologies Program in an effort to speed quantum computing technology to market.
The finance industry is particularly anxious to tap quantum computing algorithms to more accurately predict market fluctuations, but the harnessing of near-infinite computing power will revolutionize everything from decoding the human genome to programming human-like artificial intelligence.
One potential drawback of the quantum computing age is the threat to cybersecurity. Today's public key encryption technologies are based on the RSA algorithm, which encodes data in large numbers that would take conventional supercomputers literally billions of years to crack. A large enough quantum computer running a quantum equation called Shor's algorithm could break the code in seconds.
The National Security Agency (NSA) is nervous about the integrity of its encryption algorithms in the face of quantum computers, but Hensinger isn't so worried. He expects innovations in cybersecurity to keep pace.
"Researchers are already developing quantum cryptography, cryptography by the laws of physics, which is guaranteed to be safe," said Hensinger. "As long as it's reasonably public, if we know that there's a quantum computer out there, then people can take precautions. If right now there was a quantum computer that nobody knew about, then you'd have a problem."
Image: Prof. Hensinger (right) and Dr Lekitsch (left) with a quantum computing blueprint model behind a quantum computer prototype at the University of Sussex. Credit: University of Sussex.
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