QubitWire 100

In 1972, Stuart Freedman and John Clauser measured correlations between pairs of photons that violated a Bell inequality. Their measurement settings stayed fixed during each run. A decade later, Aspect, Jean Dalibard and Gérard Roger switched the settings while the photons were travelling. The correlations still exceeded the bound predicted by local hidden-variable models under the assumptions of the test. Later experiments by Aspect’s team used individual photons to study interference and ultracold atoms to see how disorder can stop matter waves from spreading.

Documented work base: France

Saffman connects the physics of individually controlled atoms to the operations a programmable quantum computer needs. His publications address both entangling several qubits and measuring selected atoms while protecting other qubits. These are distinct engineering steps: preparing useful quantum states does not by itself provide the repeated measurements required for error correction. His inclusion reflects documented experimental contributions to that progression and an active neutral-atom research program at Wisconsin.

Documented work base: United States

Schleier-Smith makes collective quantum behavior experimentally controllable. Her work uses light to mediate interactions between atoms, allowing researchers to tune how information and correlations spread through an atomic ensemble. The same ability to engineer entanglement supports both quantum simulation and improved measurement. She belongs in this directory for research that links those purposes: learning how complex quantum systems behave while developing methods to extract more precise information from them.

Documented work base: United States

Ye’s work shows how precise measurement and quantum control reinforce one another. Optical lattice clocks demand exceptional control over atoms and light; the same tools enable experiments on interactions, entanglement and ultracold molecules. His research therefore contributes to the broader experimental capabilities on which quantum computing and simulation depend. The profile highlights a measured improvement from entanglement alongside a continuing many-body research program, without presenting an atomic clock as a general-purpose quantum processor.

Documented work base: United States

Zoller helped bridge abstract quantum computation and concrete atomic experiments. The Cirac–Zoller proposal explained how trapped ions and laser control could implement quantum logic, while optical-lattice work showed how ultracold atoms could realize tunable many-body models. Both contributions give experiments a physical blueprint rather than only a mathematical target. His current identification is professor emeritus at Innsbruck; his inclusion is grounded in those collaborative architectures and their connection to quantum simulation and controlled quantum dynamics.

Documented work base: Austria