The dipolar Aleppo lattice: Ground state ordering and ergodic dynamics in the absence of vertex frustration

TL;DR

This paper introduces the Aleppo spin ice geometry, a new vertex-free lattice, and uses microscopy to observe its ground states and dynamics, highlighting the role of vertex frustration in ergodicity transitions.

Contribution

It presents the first study of the Aleppo lattice, demonstrating ground state ordering and the absence of ergodicity-breaking without vertex frustration.

Findings

Observation of ground state patterns after thermal annealing

No evidence of ergodicity-breaking dynamics

Vertex frustration is crucial for ergodicity transitions

Abstract

We introduce the Aleppo spin ice geometry, another variation of decimated square ice patterns, which in contrast to similar systems previously studied, does not exhibit vertex frustration. Using synchrotron-based photoemission electron microscopy, we directly visualize low-energy states achieved after thermal annealing, in addition to temperature-dependent moment fluctuations. The results reveal the observation of ground state patterns and the absence of ergodicity-breaking dynamics. Our observations further confirm vertex frustration to be an important criterion for the emergence of ergodicity transitions.