Microscopy of bosonic charge carriers in staggered magnetic fields

TL;DR

This paper demonstrates the realization of a bosonic $t-J$ model in a two-dimensional quantum gas microscope with a staggered magnetic field, revealing how antiferromagnetic order influences charge carrier dynamics and spin-charge correlations.

Contribution

It introduces a novel cold atom setup using negative temperature states to simulate a bosonic $t-J$ model with a staggered magnetic field, expanding the experimental toolkit for strongly correlated systems.

Findings

Memory effects influence charge carrier dynamics in antiferromagnets.

Pairs of doped holes can form bound states due to spin-charge correlations.

Staggered magnetic fields help isolate effects of antiferromagnetism on charge carriers.

Abstract

The interplay of spin and charge degrees of freedom is believed to underlie various unresolved phenomena in strongly correlated systems. Quantum simulators based on neutral atoms provide an excellent testbed for investigating such phenomena and resolving their microscopic origins. Up to now, the majority of experimental and theoretical studies has focused on systems with fermionic exchange statistics. Here we expand the existing cold atom toolbox through the use of negative temperature states, enabling us to realize an antiferromagnetic, bosonic $t-J$ model in two spatial dimensions, subject to a strong staggered magnetic field in a quantum gas microscope. Through comparison of the spreading dynamics of a single hole in a N\'eel versus a spin-polarized initial state, we establish the relevance of memory effects resulting from the buildup of strong spin-charge correlations in the dynamics of charge carriers in antiferromagnets. We further numerically predict rich dynamics of pairs of doped holes, which we demonstrate to be bound by a similar memory effect, while their center-of-mass can expand freely. Our work paves the way for the systematic exploration of the effect of antiferromagnetic spin ordering on the properties of individual charge carriers as well as finite doping phases: Our study demonstrates that the staggered field can be used to single out the effect of antiferromagnetism and holds the prospect to prepare low-temperature states in the near future.