Early Career Conference in Trapped Ions (ECCTI) 2024

Focusing of microwave-driven gate interactions using dynamical decoupling

12 Jul 2024, 11:45

22m

Hörsaal B (Technik) (Viktor-Franz-Hess Haus)

Talk 22min Quantum Information & Computing Quantum Information & Computing

Speaker

Molly Smith (University of Oxford)

Description

In trapped-ion quantum computing, quantum logic gates are often performed using lasers. Alternatively, gates can also be driven by microwave fields for which the technology is cheaper and more reliable, making it simpler to scale up. However, due to their centimetre wavelength, microwaves cannot be focused to a small spot size, making it difficult to address an individual ion within a cluster of ions confined by the same potential well.

We have proposed and demonstrated a method to enable microwave-driven entangling gate operations only in micron-sized zones, corresponding to ${10}^{-5}$ microwave wavelengths, whilst suppressing this interaction everywhere else [1]. This is done by utilising the variation in phase of a microwave-field across a surface trap. We find that the required interaction introduces $3.7(4)\times {10}^{-4}$ error per emulated gate in a single-qubit benchmarking sequence. We then 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 $\sim {10}^{-5}$.

[1] M. C. Smith et al., arXiv:2309.02125 (2023).

Presentation materials

molly_talk (1).pptx