Tetris artificial spin ice

Artificial spin ice systems are composed of arrays of interacting nanomagnets, and they were originally designed to mimic the naturally occurring frustration in real spin ice materials. The original square ice geometry [1] can be altered to give rise to an array of vertex-frustrated geometries, such as Tetris [2] and Shakti [3], that allowed the study of new interesting physics phenomena. The Tetris ice structure is composed of alternating bands of staircase and backbone nanomagnets. We conducted PEEM-XMCD experiments at varying temperatures and evaluated the Tetris ice kinetics by analyzing the resulting flipping rates and vertex fractions. We showed, in accordance with previously reported data [2], that the backbone magnetic moments are more stable than the staircases. 1. Wang et al., Nature \underline {439}, 303 (2006) 2. Gilbert et al., Nat. Phys.~\underline {12}, 162 (2016) 3. Lao et al., Nat. Phys. 14, \underline {723} (2018)