Scaling Trapped Ion Quantum Computers Using Fast Gates and Microtraps

Most attempts to produce a scalable quantum information processing platform based on ion traps have focused on the shuttling of ions in segmented traps. We show that an architecture based on an array of microtraps with fast gates will outperform architectures based on ion shuttling. This system requires higher power lasers but does not require the manipulation of potentials or shuttling of ions. This improves optical access, reduces the complexity of the trap, and reduces the number of conductive surfaces close to the ions. The use of fast gates also removes limitations on the gate time. Error rates of 10(-5) are shown to be possible with 250 mW laser power and a trap separation of 100 mu m. The performance of the gates is shown to be robust to the limitations in the laser repetition rate and the presence of many ions in the trap array.