Quantum computing with atoms

In the race to build practical quantum computers, systems based on individual neutral atoms are moving toward the front of the pack. For years, quantum bits (qubits) made from either superconducting loops or trapped ions have been the frontrunners. Increased computing power came from cramming more and more qubits into devices. This has limits because each qubit needs a separate controlling unit, and it can be tricky to get the right qubits to interact at the right time. Now, neutral-atom qubits can be created in bundles of hundreds, held in place and manipulated by laser beams called optical tweezers. Once an underdog, the technology’s pace of improvement has surprised researchers.