Measuring spectral functions of doped magnets with Rydberg tweezer arrays

TL;DR

This paper presents a novel spectroscopic protocol using Rydberg tweezer arrays to measure and image spectral functions and quasiparticles in strongly correlated quantum systems with high spatial and energy resolution.

Contribution

The authors develop a new spectroscopic method in Rydberg tweezer arrays that emulates STM, enabling direct imaging of excitations and quasiparticles in quantum many-body models.

Findings

Resolved bound magnetic polarons and measured their properties.

Demonstrated local density of states measurement across different lattice geometries.

Established Rydberg tweezer arrays as a versatile platform for quantum spectroscopy.

Abstract

Spectroscopic measurements of single-particle spectral functions provide crucial insight into strongly correlated quantum matter by resolving the energy and spatial structure of elementary excitations. Here we introduce a spectroscopic protocol for single-charge injection with simultaneous spatial and energy resolution in a Rydberg tweezer array, effectively emulating scanning tunneling microscopy. By combining this protocol with single-atom-resolved imaging, we go beyond conventional spectroscopy by not only measuring the single-particle spectral function but also directly imaging the microscopic structure of the excitations underlying spectral resonances in frustrated $tJ$ Hamiltonians. We reveal resonances associated with the formation of bound magnetic polarons -- composite quasiparticles consisting of a mobile hole bound to a magnon -- and directly extract their binding energy, spatial extent, and spin character. Finally, by exploiting the spatial tunability of our platform, we measure the local density of states across different lattice geometries. Our work establishes Rydberg tweezer arrays as a powerful platform for spectroscopic studies of strongly correlated models, offering microscopic control and direct real-space access to emergent quasiparticles in engineered quantum matter.