Southwest Quantum Information and Technology

High-fidelity two-qubit quantum gates in a scalable surface ion trap

Presenting Author: Peter Maunz, (Sandia)

Microfabricated ion traps are currently the most promising technology for scaling trapped ion quantum information processing systems to the size necessary to solve real-world problems. However, microfabricated surface traps usually have higher heating rates and a shallower trap depth than macroscopic three dimensional traps. In Sandia’s state of the art High Optical Access (HOA) trap, we have achieved heating rates at room temperature as low as 30 quanta/second (Ytterbium, 85µm from closest electrode) and have run measurements with a single ion for longer than 100 hours. Here, we present the realization of high-fidelity one- and two-qubit gates at room temperature in the HOA surface trap. We report on the first demonstration of single qubit gates above some fault-tolerance thresholds, as proven by analyzing the implemented quantum operations using Gate Set Tomography (GST) which yields a diamond distance to the target gate below 8(1) x 10^-5. Furthermore, we realize a Mølmer-Sørensen two-qubit gate and analyze the quantum operations in the symmetric subspace of the two-qubit Hilbert space using qutrit GST. For the two-qubit gate we achieve a process infidelity below 0.5%, the highest two-qubit fidelity reported to date in any scalable trap. These results demonstrate the viability of a scalable, state of the art system for quantum information processing using modern microfabricated surface ion traps.

(Session 8 : Friday from 1:30 pm - 2:15 pm)