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

We study a hardware-efficient ansatz tailored for a trapped-ion quantum simulator (HEA-TI), utilizing single-qubit rotations and global spin-spin interactions to reduce the reliance on resource-intensive multiqubit gates typical of conventional gate-based approaches. This ansatz also allows streamlined experimental control sequences with continuous global interaction and insertions of single-qubit gates. We examine the scaling behavior of quantum resources required by HEA-TI. We also apply it to the ground-state calculation of chemical molecules and examine its performance under realistic experimental noise and statistical fluctuations. Our results demonstrate that HEA-TI achieves competitive efficiency with other commonly used variational ansatzes, such as UCCSD, while offering significant implementation advantages for trapped-ion platforms.