Abstract: Artificial spin ice systems are engineered arrays of nanoscale ferromagnetic islands that provide a versatile platform for exploring geometric frustration, emergent magnetic phenomena, and collective behavior. The interactions between individual island magnetic moments give rise to complex configurations, including emergent magnetic charges and topological excitations. Recent advances have demonstrated that these collective magnetic states can be manipulated through lattice geometry and topological defects, offering new ways to control magnetic interactions and excitations.

Beyond geometric and topological engineering, the functionalization of artificial spin ice with organic molecules presents an exciting new opportunity to introduce additional mechanisms for controlling magnetic behavior. Interactions between molecular orbitals and ferromagnetic surfaces can modify the local electronic and magnetic structure, potentially producing novel interfacial phenomena. Understanding how these molecular interactions couple to the collective magnetic states of artificial spin ice remains an important open question.

In this colloquium, I will discuss approaches to investigating and controlling artificial spin ice through the combined influence of molecular functionalization, geometry, and topology. I will highlight how topological defects can influence magnetic charge distributions and collective excitations, as well as how organic molecular decorations may provide new routes for modifying local magnetic interactions. I will also discuss the use of complementary magnetic and optical imaging techniques, including magnetic force microscopy, X-ray photoemission electron microscopy, and fluorescence photoactivation and localization microscopy, to probe these systems across multiple length and time scales. Together, these approaches offer new opportunities to understand and engineer emergent magnetic behavior, with potential applications in tunable spintronic devices and magnetic sensing.

Bio: Dr. Bingham received his Ph.D. in Physics from the University of South Florida in 2013, focusing on phase transitions in 0-, 1-, 2-, and 3-dimensional materials, with a strong emphasis on magnetic phase transitions. He held a joint postdoctoral fellowship with ETH-Zürich and the Paul Scherrer Institute, a National Research Council postdoctoral fellowship with the Naval Research Laboratory, and research faculty position at Yale University. Currently, he holds a joint Assistant Professor of Physics and Astronomy and the Frontier Institute for Research in Sensor Technologies at the University of Maine. His research focuses on strongly correlated electron thin films and artificial spin ice, with an emphasis on thin-film growth and characterization. He has recently received the NSF CAREER award and has over 60 publications.