Microscope upgrade tracks individual energy carriers through materials

Columbia researchers demonstrated a microscope technique that distinguishes individual quantum energy carriers as they move through materials, including single electrons in a two-dimensional semiconductor. The work, published in Nature Materials, extends an instrument previously limited to measurements at high carrier densities. The microscope, called stroboSCAT, uses pulses of light to track energy transport. Cycling the light intensity lets researchers separate single-particle behavior from interactions among multiple particles. The team also tracked two-particle and three-particle states and mapped how crystal defects affect a semiconductor's electronic environment. Research leader Milan Delor is making the instrument's blueprints and software available and helping other laboratories implement it.