Individually Addressed Quantum Gate Interactions Using Dynamical Decoupling

A leading approach to implementing small-scale quantum computers has been to use laser beams, focused to micron spot sizes, to address and entangle trapped ions in a linear crystal. Here we propose a method to implement individually addressed entangling gate interactions, but driven by microwave fields, with a spatial resolution of a few microns, corresponding to <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><a:msup><a:mn>10</a:mn><a:mrow><a:mo>−</a:mo><a:mn>5</a:mn></a:mrow></a:msup></a:math> microwave wavelengths. We experimentally demonstrate the ability to suppress the effect of the state-dependent force using a single ion, and find the required interaction introduces <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><d:mn>3.7</d:mn><d:mo stretchy="false">(</d:mo><d:mn>4</d:mn><d:mo stretchy="false">)</d:mo><d:mo>×</d:mo><d:msup><d:mn>10</d:mn><d:mrow><d:mo>−</d:mo><d:mn>4</d:mn></d:mrow></d:msup></d:math> error per emulated gate in a single-qubit benchmarking sequence. We model the scheme for a 17-qubit ion crystal, and find that any pair of ions should be addressable with an average crosstalk error of approximately <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><i:msup><i:mn>10</i:mn><i:mrow><i:mo>−</i:mo><i:mn>5</i:mn></i:mrow></i:msup></i:math>. Published by the American Physical Society 2024