The decades-long quest to create a practical quantum computer is accelerating as major tech companies say they are closing in on designs that could scale from small lab experiments to full working systems within just a few years.
IBM laid out a detailed plan for a large-scale machine in June, filling in gaps from earlier concepts and declaring it was on track to build one by the end of the decade.
“It doesn’t feel like a dream anymore,” Jay Gambetta, head of IBM’s quantum initiative, told Financial Times.
“I really do feel like we’ve cracked the code and we’ll be able to build this machine by the end of the decade.”
Google, which cleared one of the toughest technical obstacles late last year, says it is also confident it can produce an industrial-scale system within that time frame, while Amazon Web Services cautions that it could still take 15 to 30 years before such machines are truly useful.
Quantum computing is a new kind of computing that doesn’t just think in 0s and 1s like today’s computers.
Instead, it uses qubits — tiny quantum bits — that can be 0, 1, or both at the same time.
This lets quantum computers explore many possibilities at once and find answers to certain complex problems much faster than normal computers.
Quantum computing could speed up the discovery of new drugs and treatments, make artificial intelligence systems faster and more capable and improve the accuracy of market predictions and fraud detection in finance.
It could also dramatically improve efficiency in areas like traffic routing, shipping, energy grids and supply chains while driving green innovation by helping design better batteries, cleaner energy systems and more sustainable technologies.
But scaling them up from fewer than 200 qubits — the quantum version of a computing bit — to over 1 million will require overcoming formidable engineering challenges.
Qubits are inherently unstable, maintaining their special quantum states for only fractions of a second, and adding more of them can create interference that scrambles calculations.
Even if the fundamental physics problems are solved, the industry still faces the task of industrializing quantum technology.
This means building chips that can house large numbers of qubits, and developing much bigger refrigeration units to keep the systems at near absolute zero.
Systems using superconducting qubits, like those from IBM and Google, have made some of the fastest progress but require extreme cooling and are difficult to control.
Meanwhile, some companies are betting on radically new qubit designs.
Amazon and Microsoft claim to have harnessed a new state of matter to produce more reliable components, although these are still in early development.
“Just because it’s hard, doesn’t mean it can’t be done,” Mark Horvath, an analyst at Gartner, told FT.