Quantum computing

A new result shows that quantum information can theoretically be protected from errors just as well as classical information can.

Puzzling particles, quirky (and controversial) quantum computers, and one of the most ambitious science experiments in history marked the year’s milestones.

One of the first goals of quantum computing has been to recreate bizarre quantum systems that can’t be studied in an ordinary computer. A dark-horse quantum simulator has now done just that.

Quantum bits are fussy and fragile. Useful quantum computers will need to use an error-correction technique like the one that was recently demonstrated on a real machine.

So-called topological quantum computing would avoid many of the problems that stand in the way of full-scale quantum computers. But high-profile missteps have led some experts to question whether the field is fooling itself.

Like a perpetual motion machine, a time crystal forever cycles between states without consuming energy. Physicists claim to have built this new phase of matter inside a quantum computer.

To understand what quantum computers can do — and what they can’t — avoid falling for overly simple explanations.

The secret to making a qubit for future quantum computers might depend on knowing how to tie knots in unusual materials, argues the physicist Charlie Marcus.

Two teams found different ways for quantum computers to process nonlinear systems by first disguising them as linear ones.