Group seminar at MPQ and Zoom: Single-ion addressing using crossed acousto-optic deflectors

Hendrik Timme, ETH Zurich
Group seminar at MPQ lecture hall and Zoom
Thursday, August 10, 09:00am (MEZ)

Abstract:
This work presents the characterization of a single-ion addressing setup for trapped 40Ca+ ions. Quantum computers have the potential to provide exponential speedup for certain problems, and error correction is crucial to achieving this. Bosonic codes are a promising class of error-correcting codes that can be implemented in trapped ions. To scale up the system to several ions and reach the break-even point in error correction, individual addressing of ions and high Rabi frequencies are essential.

In this work, we characterize a single-ion addressing setup using crossed acousto-optic deflectors. We also determine the spot size, operational crosstalk, and beam-pointing error. Our measurements show a horizontal beam waist of less than 2 μm and operational crosstalk of less than 10−^3 for ions that are 5 μm apart. We develop a model describing fluctuations in the beam position to show that the beam deviates by  less than 21 nm. We also adapt an algorithm to determine the aberrations using an ion to image the laser beam. Our results show that it is a viable system to do fast single-ion addressing with the potential to be used in bosonic encodings in trapped ions.