Control cold-atom quatum computer

ScaleAtom

PlacePrinceton · Thompson Group

FieldCold-atom quantum computing

PeriodFall 2021

Fig. 1 — Optical tweezer array for the Yb-171 atoms.

Fig. 2 — Princeton cold-atom optical setup, top-half view (looping clip).

Problem. Neutral-atom quantum computers depend on preparing atoms into the correct clock state (3P0 for Yb171) before performing quantum operations. This is achieved through optical pumping, which demands precise control over laser frequencies, power, and magnetic field strength. Intuition alone is insufficient to select a reliable configuration.

What we did. To address this challenge, we implemented a simulation of an optical pumping scheme using QuTiP, a quantum module in Python. To validate the simulation results, a custom Python differential equation solver was also developed to generate simple test cases. Additionally, a PID-controlled laser was incorporated into the real experiment, allowing us to compare simulation outcomes with actual conditions.

Result. The simulation accurately estimated the necessary laser and magnetic-field power required to prepare the quantum computer into its initial state, akin to turning on a computer. This lightweight simulation tool can be used to model the conditions necessary for the laser system to emit light.

Why it matters. Rare-earth neutral-atom arrays is a promising platform to be the first practical quantum computer. These arrays have the capability to transform complex computational tasks into solvable ones through high parallelization, paving the way for advancements in quantum computing.