Realization of a doped quantum antiferromagnet in a Rydberg tweezer array.

Abstract

Doping an antiferromagnetic (AFM) Mott insulator is central to our understanding of a variety of phenomena in strongly correlated electrons, including high-temperature superconductors^1,2. To describe the competition between tunnelling t of hole dopants and AFM spin interactions J, theoretical and numerical studies often focus on the paradigmatic t-J model³ and the direct analogue quantum simulation of this model in the relevant regime of high-particle density has long been sought^4,5. Here we realize a doped quantum antiferromagnet with next-nearest-neighbour (NNN) tunnellings t' (refs. ^6-10) and hard-core bosonic holes¹¹ using a Rydberg tweezer platform. We use coherent dynamics between three Rydberg levels, encoding spins and holes¹², to implement a tunable bosonic t-J-V model allowing us to study previously inaccessible parameter regimes. We observe dynamical phase separation between hole and spin domains for |t/J| ≪ 1 and demonstrate the formation of repulsively bound hole pairs in a variety of spin backgrounds. The interference between NNN tunnellings t' and perturbative pair tunnelling gives rise to light and heavy pairs depending on the sign of t. Using the single-site control allows us to study the dynamics of a single hole in 2D square lattice (anti)ferromagnets. The model we implement extends the toolbox of Rydberg tweezer experiments beyond spin-1/2 models¹³ to a larger class of t-J and spin-1 models^14,15.