Study of thermal kinetics in artificial spin ice systems

Artificial spin ice;magnetism

Lao, Yuyang

关键词: Artificial spin ice;    magnetism;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/101461/LAO-DISSERTATION-2018.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Artificial spin ice is a two-dimensional array of nanomagnets fabricated to study geometric frustration, a phenomenon that arises when competing interactions cannot be simultaneously satisfied within the system. While the ground states of these artificial systems have been previously studied, this thesis focuses on the dynamic process around the ground state of these systems. In addition to the original square artificial spin ice, we also examine a collection of vertex-frustrated lattices. These lattices can be designed and fabricated easily with great flexibility while yielding fruitful physics insight about the frustrated systems. We discuss the necessary background and techniques related to the study. Using a Shakti lattice, we investigate a mechanism that blocks the system from relaxing into a degenerate ground state through a classical topology framework. Then we discuss the efforts to thermalize artificial spin ice system better and advance the understanding of thermal annealing process. Lastly, we study two lattices, a tetris lattice and Santa Fe lattices, on the transitions among their degenerate ground states and the related dynamic process. These efforts serve as a collective advancement in understanding the thermal kinetics of artificial spin ice systems.