Unconventional spin transport in strongly correlated kagome systems

TL;DR

This paper demonstrates that unconventional spin transport can occur at high temperatures in strongly correlated kagome systems due to emergent dynamical constraints, revealing new transport phenomena in these materials.

Contribution

It introduces a novel mechanism for high-temperature spin transport in kagome systems driven by emergent dynamical constraints and hidden conservation laws.

Findings

Unconventional spin transport arises at elevated temperatures.

Charge dynamics can be described by a Gaussian height field theory.

Hidden spin conservation laws enable slow relaxation pathways.

Abstract

Recent progress in material design enables the study of correlated, low-temperature phases and associated anomalous transport in two-dimensional kagome systems. Here, we show that unconventional spin transport can arise in such systems even at elevated temperatures due to emergent dynamical constraints. To demonstrate this effect, we consider a strong-coupling limit of an extended Hubbard model on the kagome lattice with density of $2/3$. We numerically investigate the charge and spin transport by a cellular automaton circuit, allowing us to perform simulations on large systems to long times while preserving the essential conservation laws. The charge dynamics reflects the constraints and can be understood by a Gaussian field theory of a scalar height field. Moreover, the system exhibits a hidden spin conservation law with a dynamic sublattice structure, which enables additional slow relaxation pathways for spin excitations. These features can be directly tested by measuring the dynamic spin structure factor with neutron scattering.