A new look on the two-dimensional Ising model: thermal artificial spins

TL;DR

This paper experimentally investigates thermal ordering in a nano-fabricated artificial 2D Ising system, revealing how island thickness influences thermal fluctuations and magnetic states, thus providing a physical realization of the Ising model.

Contribution

It introduces a novel experimental platform for studying the 2D Ising model using nano-fabricated magnetic islands and analyzes the effects of thermal fluctuations and fabrication parameters.

Findings

Thermal fluctuations occur below a critical island thickness.

Above the critical thickness, islands become frozen, leading to arrested states.

The system behaves as a genuine 2D Ising model with nearest neighbor interactions.

Abstract

We present a direct experimental investigation of the thermal ordering in an artificial analogue of an asymmetric two dimensional Ising system composed of a rectangular array of nano-fabricated magnetostatically interacting islands. During fabrication and below a critical thickness of the magnetic material the islands are thermally fluctuating and thus the system is able to explore its phase space. Above the critical thickness the islands freeze-in resulting in an arrested thermalized state for the array. Determining the magnetic state of the array we demonstrate a genuine artificial two-dimensional Ising system which can be analyzed in the context of nearest neighbour interactions.