Toroidic phase transitions in a direct-kagome artificial spin ice
Abstract
Ferrotoroidicity, the fourth form of primary ferroic order, breaks both space and time inversion symmetry. So far, direct observation of ferrotoroidicity in natural materials remains elusive, which impedes the exploration of ferrotoroidic phase transitions. Here, we overcome the limitations of natural materials using an artificial nanomagnet system that can be characterized at the constituent level and at different effective temperatures. We design a nanomagnet array as to realize a direct-kagome spin ice. This artificial spin ice exhibits robust toroidal moments and a quasi-degenerate ground state with two distinct low-temperature toroidal phases: ferrotoroidicity and paratoroidicity. Using magnetic force microscopy and Monte Carlo simulation, we demonstrate a phase transition between ferrotoroidicity and paratoroidicity, along with a crossover to a non-toroidal paramagnetic phase. Our quasi-degenerate artificial spin ice in a direct-kagome structure provides a model system for the investigation of magnetic states and phase transitions that are inaccessible in natural materials.
Keywords
Cite
@article{arxiv.2404.19377,
title = {Toroidic phase transitions in a direct-kagome artificial spin ice},
author = {Wen-Cheng Yue and Zixiong Yuan and Peiyuan Huang and Yizhe Sun and Tan Gao and Yang-Yang Lyu and Xuecou Tu and Sining Dong and Liang He and Ying Dong and Xun Cao and Lin Kang and Huabing Wang and Peiheng Wu and Cristiano Nisoli and Yong-Lei Wang},
journal= {arXiv preprint arXiv:2404.19377},
year = {2024}
}