Cyclic Memories in Disordered Matter
Date: Thursday, January 24th, 2019
Location: 100 Willamette Hall
Speaker: Nathan Keim, Polytechnic State University
Cyclic driving happens all around us. Buildings and bridges are repeatedly loaded and unloaded, and temperatures change between day and night. This kind of driving can change a material, but in some cases it also forms memories that can be recalled later. I present two examples of materials that, when deformed repeatedly, can “learn” and report the magnitudes of those deformations: a suspension of particles in liquid, and a jammed solid made of closely packed particles. Their memories follow different rules, with jammed solids approximating the return-point behavior best known in magnetic materials. These materials’ disordered structure, and sometimes even the presence of noise, are essential for the fidelity of their memories.
Host: Eric Corwin
All attendees are invited to attend a colloquium reception in the Willamette Hall, Paul Olum atrium at 3:40pm.