# Milestones in Quantum Computing

In a paper in the Journal of Statistical Physics, Paul Benioff of Argonne National Laboratory describes the feasibility of a computer that uses quantum effects to make calculations.

Richard Feynman shows how such a computer could be used to accurately simulate quantum processes in nature.

The physicist David Deutsch shows that quantum computers could be “universal”—able to simulate any physical process.

MIT’s Peter Shor demonstrates how a quantum computer could quickly determine the prime factors of very large numbers. That capability would render many contemporary cryptographic protocols useless.

Lov Grover of Bell Labs develops an algorithm that a quantum computer could use to search through any database far faster than a conventional machine could.

Two research groups, working independently, each carry out basic quantum calculations by making quantum bits, or qubits, out of molecules that they manipulate with radio waves.

A Canadian startup, D-Wave Systems, unveils what it says is the world’s first commercial quantum computer. Whether this machine actually exploits quantum effects will be debated for several years, but even D-Wave agrees that its machines are not universal quantum computers. They are fundamentally limited to solving one kind of problem.

Caltech physicist John Preskill describes "quantum supremacy": the point at which quantum computers can be controlled well enough to reliably outperform classical digital computers.

Researchers at Google, Lawrence Berkeley National Laboratories, and several universities use three qubits to simulate the energy states of a hydrogen molecule.

IBM announces the commercial release of a computer with 20 qubits. It’s meant for researchers and other early adopters but isn’t yet a game-changer. Its qubits aren’t very stable, and 20 of them can’t produce the computational power that quantum computing promises.

Google researchers claim to have achieved quantum supremacy. They say they have used a machine with 53 qubits to solve a problem in three minutes that would have taken the fastest classical computer 10,000 years. IBM, which disputes whether Google's experiment truly proves quantum supremacy, also begins offering access to a computer with 53 qubits.