Wang Chenxi, Huang Chuanxin, Zhang Hongxuan, Hu Hongyuan, Mao Zhichao, Hou Panyu, Wu Yukai, Zhou Zichao, Duan Luming
Tsinghua University, Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Beijing 100084, People's Republic of China.
HYQ Co., Ltd., Beijing 100176, People's Republic of China.
Phys Rev Lett. 2025 Jan 10;134(1):010601. doi: 10.1103/PhysRevLett.134.010601.
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 S_{1/2} and D_{5/2} hyperfine manifolds of ^{137}Ba^{+} ions. Our scheme is economic in the hardware, requiring only a single 532 nm 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.
