The world ’ s fastest supercomputer , launched by the U . S . Department of Energy in November 2022 , can perform more than a quintillion calculations per second .
To achieve this feat , the entire global population would have to crunch the same arithmetical problem for five years . Although the capabilities of this first exascale computer are remarkable , they ’ re not nearly enough to solve some of the world ’ s most pressing problems .
Take fertilizer production , which uses 2 – 3 % of the world ’ s entire energy consumption . As much as 90 % of that energy goes to making ammonia through nitrogen fixation . Making this process more energy-efficient would involve simulating such a large number of chemical interactions that it could take classical computers billions of years , and even a supercomputer couldn ’ t achieve it in “ reasonable time .”
Quantum computing promises to break through the limitations of classical computers — even high-performing ones like supercomputers — to solve these kinds of “ unsolvable ” problems . They could help achieve anything from understanding the nitrogen fixation process to explaining the mysteries of dark matter . In theory , anyway .
Scientists must first learn to control large numbers of quantum bits — tiny particles such as atoms , electrons or photons that hold quantum information . And these quantum bits , or qubits , are very unruly , behaving in ways that are nothing like the classical computer bits .
“ The science tells us that these quantum devices , if we ’ re able to build them , will make an incredible difference in a set of very specific problems .”
A fundamentally different technology Raymond Laflamme , Canada research chair in quantum computing at the University of Waterloo in Canada , says there ’ s a fundamental difference between quantum and classical computing .
“ There ’ s an exponential gap between quantum computers and classical ones ,” he says . “ The science tells us that these quantum devices , if we ’ re able to build them , will make an incredible difference in a set of very specific problems , and they do this in a really surprising way compared to the computers that we have around today .”
These surprising ways — based on the principles of quantum physics — allow quantum computers to process information much faster , especially when performing tasks such as quantum simulations , optimization and large number factorization .
— Raymond Laflamme , Canada research chair , quantum computing , University of Waterloo
ILLUSTRATIONS BY KEITH NEGLEY
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