Quantum computing

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.

The result highlights a fundamental tension: Either the rules of quantum mechanics don’t always apply, or at least one basic assumption about reality must be wrong.

Can we test speculations about how quantum physics affects black holes and the Big Bang?

A landmark proof in computer science has also solved an important problem called the Connes embedding conjecture. Mathematicians are working to understand it.

Computer scientists established a new boundary on computationally verifiable knowledge. In doing so, they solved major open problems in quantum mechanics and pure mathematics.

A curious physicist has discovered an unexpected link between theoretical block collisions and a famed quantum search algorithm.