Kinetic pathways to the magnetic charge crystal in artificial dipolar spin ice

TL;DR

This study explores how artificial kagome spin ice systems undergo kinetic pathways during cooling, leading to magnetic charge crystal formation through out-of-equilibrium processes, with experimental results supported by simulations.

Contribution

It reveals the kinetic pathways and out-of-equilibrium dynamics involved in the formation of magnetic charge crystals in artificial dipolar spin ice.

Findings

Arrays reach a spin ice 2 phase with magnetic charge order.

Signatures of out-of-equilibrium physics are observed.

Thermalization efficiency is linked to kinetic pathways during cooling.

Abstract

We investigate experimentally magnetic frustration effects in thermally active artificial kagome spin ice. Starting from a paramagnetic state, the system is cooled down below the Curie temperature of the constituent material. The resulting magnetic configurations show that our arrays are locally brought into the so-called spin ice 2 phase, predicted by at-equilibrium Monte Carlo simulations and characterized by a magnetic charge crystal embedded in a disordered kagome spin lattice. However, by studying our arrays on a larger scale, we find unambiguous signature of an out-of-equilibrium physics. Comparing our findings with numerical simulations, we interpret the efficiency of our thermalization procedure in terms of kinetic pathways that the system follows upon cooling and which drive the arrays into degenerate low-energy manifolds that are hardly accessible otherwise.