Dipolar spin-exchange and entanglement between molecules in an optical tweezer array

Yicheng Bao; Scarlett S Yu; Loïc Anderegg; Eunmi Chae; Wolfgang Ketterle; Kang-Kuen Ni; John M Doyle

doi:10.1126/science.adf8999

Dipolar spin-exchange and entanglement between molecules in an optical tweezer array

Science. 2023 Dec 8;382(6675):1138-1143. doi: 10.1126/science.adf8999. Epub 2023 Dec 7.

Authors

Yicheng Bao^{1

2}, Scarlett S Yu^{1

2}, Loïc Anderegg^{1

2}, Eunmi Chae³, Wolfgang Ketterle^{2

4}, Kang-Kuen Ni^{1

2

5}, John M Doyle^{1

2}

Affiliations

¹ Department of Physics, Harvard University, Cambridge, MA 02138, USA.
² Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA.
³ Department of Physics, Korea University, Seongbuk-gu, Seoul 02841, South Korea.
⁴ Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
⁵ Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.

PMID: 38060651
DOI: 10.1126/science.adf8999

Abstract

Ultracold polar molecules are promising candidate qubits for quantum computing and quantum simulations. Their long-lived molecular rotational states form robust qubits, and the long-range dipolar interaction between molecules provides quantum entanglement. In this work, we demonstrate dipolar spin-exchange interactions between single calcium monofluoride (CaF) molecules trapped in an optical tweezer array. We realized the spin-[Formula: see text] quantum XY model by encoding an effective spin-[Formula: see text] system into the rotational states of the molecules and used it to generate a Bell state through an iSWAP operation. Conditioned on the verified existence of molecules in both tweezers at the end of the measurement, we obtained a Bell state fidelity of 0.89(6). Using interleaved tweezer arrays, we demonstrate single-site molecular addressability.