No small feat: using quantum mechanics to see atoms, molecules and electrons at surfaces

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 Tunneling Microscopy (STM) uses this phenomenon of quantum tunneling to give a unique view of materials, creating images of the atomic scale structure and quantum states of surfaces by scanning a tunneling 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.

Dr. Sarah Burke's research uses scanning probe microscopy techniques to investigate a wide range of materials from the atomic scale up. Burke received her Bachelor’s Degree from Dalhousie University in 2002 (Honours in Physics) and her Master’s and Doctoral Degrees in Physics from McGill University in 2004 and 2009 respectively, where she focused on studying the growth and epitaxy molecules on insulating surfaces using non-contact atomic force microscopy. She then held an NSERC Postdoctoral Fellowship at UC Berkeley with Michael Crommie where she investigated graphene nano-structures using low temperature scanning tunnelling microscopy and spectroscopy. Since arriving at the University of British Columbia in 2010 as a member of both the Physics & Astronomy Department, and Chemistry Department she has been building an interdisciplinary research group approaching materials questions from the atomic scale. She has held the Canada Research Chair (Tier 2) in Nanoscience since 2010, and received a Peter Wall Early Career Scholar Award for Interdisciplinary study 2011-2012. Her group at UBC, part of the Stewart Blusson Quantum Matter Institute, applies the suite of scanning probe microscopy techniques to diverse materials ranging from superconductors to organic materials for future devices.