Towards artificial Ising spin glasses: Thermal ordering in randomized arrays of Ising-type nanomagnets

Author(s): Saccone, Michael; Scholl, Andreas; Velten, Sven; Dhuey, Scott; Hofhuis, Kevin; Wuth, Clemens; Huang, Yen-Lin; Chen, Zuhuang; Chopdekar, Rajesh V; Farhan, Alan | Abstract: © 2019 American Physical Society. We explore the thermodynamics in two-dimensional arrays consisting of Ising-type nanomagnets lithographically arranged onto random sites and angular orientations. Introducing these basic spin-glass ingredients, we study the characteristic features of the low-energy states achieved, following thermal-annealing protocols. From direct visualization of real-time dynamics, we record relaxation timescales together with magnetic susceptibility variations over temperature, revealing trends towards short-range order as randomness is increased, but falling short of pure spin-glass behavior. Our work provides a route towards the realization of artificial Ising spin-glass systems.