Scientists built a quantum gate linking four-state photons, showing complex quantum tasks can be done with fewer steps using qudits.

Olival Freire Jr is a professor of physics and the history of physics at the Federal University of Bahia, Brazil. What makes matter stable? Why are atoms as they are? Why do different materials vary ...

A century ago, the strange behavior of atoms and elementary particles led physicists to formulate a new theory of nature. That theory, quantum mechanics, found immediate success, proving its worth ...