Scalable and Parallel Tweezer Gates for Quantum Computing with Long Ion Strings

TL;DR

This paper introduces a scalable method for implementing parallel entangling gates in long ion chains by engineering localized phonon modes with optical tweezers, enabling efficient quantum computing expansion.

Contribution

It presents a novel approach to scalable quantum gates using localized phonon modes tailored by optical tweezers, facilitating parallel operations in long ion chains.

Findings

Localized phonon modes enable parallel entangling gates.

Analytical and numerical validation for long and infinite ion chains.

Combining methods with optimal control achieves dense universal quantum circuits.

Abstract

Trapped-ion quantum computers have demonstrated high-performance gate operations in registers of about ten qubits. However, scaling up and parallelizing quantum computations with long one-dimensional (1D) ion strings is an outstanding challenge due to the global nature of the motional modes of the ions which mediate qubit-qubit couplings. Here, we devise methods to implement scalable and parallel entangling gates by using engineered localized phonon modes. We propose to tailor such localized modes by tuning the local potential of individual ions with programmable optical tweezers. Localized modes of small subsets of qubits form the basis to perform entangling gates on these subsets in parallel. We demonstrate the inherent scalability of this approach by presenting analytical and numerical results for long 1D ion chains and even for infinite chains of uniformly spaced ions. Furthermore, we show that combining our methods with optimal coherent control techniques allows to realize maximally dense universal parallelized quantum circuits.