Assembling a Ring-Shaped Crystal in a Microfabricated Surface Ion Trap

Using an ensemble of ions to register one qubit each, the so-called trapped ion quantum computer could serve as a universal computing machine, with the advantages in speed and power that a quantum device could bring. However, actually making a suitably large trap is far from trivial. The authors microfabricate a ring-shaped ion trap and demonstrate its storage of 400 evenly spaced calcium ions. Its circularly symmetric trapping potential furthermore enables fundamental experiments on e.g. simulated Hawking radiation or the Aharonov-Bohm effect.