Thompson Rivers University

The surfaces of atoms, molecules and electrons using quantum mechanics

Science Seminar Series: presents No small feat: using quantum mechanics to see atoms, molecules and electrons at surfaces, by Dr. Sarah Burk, M.Sc., Ph.D. Physics (McGill Univ.); Member of Physics & Astronomy and Chemistry Dept., UBC; Canada Research Chair (Tier 2) Nanoscience; UBC Research Group—Part of Stewart Blusson Quantum Matter Institute.

Abstract

Quantum tunneling is one of the features of quantum mechanics that captures the imagination, with particles able to pass directly through barriers instead of over them. Scanning Tunnelling Microscopy (STM) uses this phenomenon of quantum tunnelling to give a unique view of materials, creating images of the atomic scale structure and quantum states of surfaces by scanning a tunnelling tip over a surface a mere atom’s width away.

The information that can be obtained about the real-space electron density, and energy dependence of the density of states provides us with insight into electronic transport, optoelectronic properties, magnetism and reactivity of materials.

Together with a suite of related techniques collectively known as Scanning Probe Microscopy (SPM), these versatile methods have had impact in fields as diverse as biology and quantum computing.

Using my group’s work, I will show examples of how SPM can be used to characterize the electronic landscapes that drive charge separation in organic solar cells, influence reactivity, and give rise to superconductivity and other electronic phases in quantum materials.

These diverse topics have surprising commonalities in the underlying ways in which electrons in materials interact. I will describe the process of discovery in these vignettes to highlight the sometimes winding—and exciting—path that research can take.