Dual-type qubits have become a promising way to suppress the crosstalk error of auxiliary operations in large-scale ion trap quantum computation. Here we demonstrate a direct entangling gate between dual-type qubits encoded in the S1/2 and D5/2 hyperfine manifolds of 137Ba+ ions. Our scheme is economic in the hardware, requiring only a single 532nm laser system to entangle both qubit types by driving their Raman transitions. We achieve a Bell state fidelity of 96.3(4)% for the dual-type Molmer-Sorensen gate between an S-D ion pair, comparable to that for the same-type S-S or D-D gates. This technique can reduce the overhead for back-and-forth conversions between dual-type qubits in the quantum circuit with wide applications in quantum error correction and ion-photon quantum networks.
@article{arxiv.2410.05659,
title = {Experimental realization of direct entangling gates between dual-type qubits},
author = {Chenxi Wang and Chuanxin Huang and Hongxuan Zhang and Hongyuan Hu and Zhichao Mao and Panyu Hou and Yukai Wu and Zichao Zhou and Luming Duan},
journal= {arXiv preprint arXiv:2410.05659},
year = {2025}
}