Hardware-efficient variational quantum algorithm in trapped-ion quantum computer

TL;DR

This paper introduces a hardware-efficient variational quantum algorithm tailored for trapped-ion quantum computers, reducing resource requirements and demonstrating effectiveness in state engineering and molecular ground state problems.

Contribution

The paper presents a novel ansatz for trapped-ion quantum computers that minimizes resource use and simplifies implementation compared to traditional methods.

Findings

Comparable efficiency to UCCSD ansatz

Effective in state engineering of cluster states

Successfully applied to molecular ground state problems

Abstract

We study a hardware-efficient variational quantum algorithm ansatz tailored for the trapped-ion quantum simulator, HEA-TI. We leverage programmable single-qubit rotations and global spin-spin interactions among all ions, reducing the dependence on resource-intensive two-qubit gates in conventional gate-based methods. We apply HEA-TI to state engineering of cluster states and analyze the scaling of required quantum resources. We also apply HEA-TI to solve the ground state problem of chemical molecules $\mathrm{H_{2}}$, $\mathrm{LiH}$ and $\mathrm{F_{2}}$. We numerically analyze the quantum computing resources required to achieve chemical accuracy and examine the performance under realistic experimental noise and statistical fluctuation. The efficiency of this ansatz is shown to be comparable to other commonly used variational ansatzes like UCCSD, with the advantage of substantially easier implementation in the trapped-ion quantum simulator. This approach showcases the hardware-efficient ansatz as a powerful tool for the application of the near-term quantum computer.