Observation of Entangled States of a Fully Controlled 20-Qubit System
Nicolai Friis, Oliver Marty, Christine Maier, Cornelius Hempel, Milan Holzäpfel, Petar Jurcevic, Martin Bodo Plenio, Marcus Huber, Christian F. Roos, R. Blatt, B. P. Lanyon · Physical Review X · 2018
Two new methods for detecting quantum entanglement---a critical ingredient for useful quantum technologies---successfully do so in a system of 20 qubits, the largest fully controllable entangled system to date.