To keep
qubits used in quantum computers cold enough so scientists can study them,
DOE’s Lawrence Berkeley National Laboratory uses a sophisticated cooling
system.
Credit: Image courtesy of Thor Swift, Lawrence Berkeley National
Laboratory
A
quintillion calculations a second. That’s one with 18 zeros after it. It’s the
speed at which an exascale supercomputer will process information. The
Department of Energy (DOE) is preparing for the first exascale computer to be
deployed in 2021. Two more will follow soon after. Yet quantum computers may be
able to complete more complex calculations even faster than these up-and-coming
exascale computers. But these technologies complement each other much more than
they compete.
It’s going
to be a while before quantum computers are ready to tackle major scientific
research questions. While quantum researchers and scientists in other areas are
collaborating to design quantum computers to be as effective as possible once
they’re ready, that’s still a long way off. Scientists are figuring out how to
build qubits for quantum computers, the very foundation of the technology.
They’re establishing the most fundamental quantum algorithms that they need to
do simple calculations. The hardware and algorithms need to be far enough along
for coders to develop operating systems and software to do scientific research.
Currently, we’re at the same point in quantum computing that scientists in the
1950s were with computers that ran on vacuum tubes. Most of us regularly carry
computers in our pockets now, but it took decades to get to this level of
accessibility.
In
contrast, exascale computers will be ready next year. When they launch, they’ll
already be five times faster than our fastest computer – Summit, at Oak Ridge
National Laboratory’s Leadership Computing Facility, a DOE Office of Science
user facility. Right away, they’ll be able to tackle major challenges in
modeling Earth systems, analyzing genes, tracking barriers to fusion, and more.
These powerful machines will allow scientists to include more variables in
their equations and improve models’ accuracy. As long as we can find new ways
to improve conventional computers, we’ll do it.
Once
quantum computers are ready for prime time, researchers will still need
conventional computers. They’ll each meet different needs.
DOE is
designing its exascale computers to be exceptionally good at running scientific
simulations as well as machine learning and artificial intelligence programs.
These will help us make the next big advances in research. At our user
facilities, which are producing increasingly large amounts of data, these
computers will be able to analyze that data in real time.
Quantum
computers, on the other hand, will be perfect for modeling the interactions of
electrons and nuclei that are the constituents of atoms. As these interactions
are the foundation for chemistry and materials science, these computers could
be incredibly useful. Applications include modeling fundamental chemical
reactions, understanding superconductivity, and designing materials from the
atom level up. Quantum computers could potentially reduce the time it takes to
run these simulations from billions of years to a few minutes. Another
intriguing possibility is connecting quantum computers with a quantum internet
network. This quantum internet, coupled with the classical internet, could have
a profound impact on science, national security, and industry.
Just as
the same scientist may use both a particle accelerator and an electron
microscope depending on what they need to do, conventional and quantum
computing will each have different roles to play. Scientists supported by the
DOE are looking forward to refining the tools that both will provide for
research in the future.