Condensed Matter Student Seminar Series

Description

Title: CO2 Laser Substrate Heating: The Most Interesting Solution to Epitaxy’s Most Boring Problem

Abstract: Epitaxy is utilized to build crystals with historically inaccessible dimensions, interfaces, and strain states, making it popular among engineers and condensed matter physicists. Whether practitioners are trying to scale a practical device or study intrinsic physics, they want to repeatably synthesize epitaxial films with low defect densities. For some crystals, repeatable epitaxial synthesis is no problem, which enabled discovery of the blue LED and fractional quantum Hall effect, each resulting in a Nobel Prize. Other crystals, particularly complex oxides, are popular research topics, but repeatable, epitaxial synthesis has remained elusive because their stoichiometry cannot be thermodynamically controlled using conventional substrate heaters. In my talk, I will share our synthetic progress using CO2 laser substrate heating technology to expand the suite of epitaxial crystals that can be grown with thermodynamic control over stoichiometry. In a year and a half, this disruptive technology has already enabled our lab to repeatably fabricate ferroelectric BaTiO3 with high structural fidelity, and experimentally observe the band structure of the most conducting perovskite, SrMoO3.