Combining molecular beam epitaxy and scanning probe microscopy to understand and control the nanoscale electronic and magnetic properties of exotic materials.

Surface band structure of SmB6 obtained through quasiparticle interference measurements.

Research in the Hoffman laboratory is motivated by the conviction that technological solutions are driven by new materials, and that the materials frontier lies in the design of emergent properties at interfaces and small length scales. Our research combines atomic layer-by-layer growth and atomic resolution imaging of materials, to uncover new physics and applications inaccessible via bulk synthesis and probes. We have used scanning tunneling microscopy (STM) and magnetic force microscopy (MFM) to investigate fundamental mechanisms of electron pairing and technical challenges of vortex pinning in high-Tc superconductors. We have used conducting atomic force microscopy (CAFM) to control the metal-insulator transition in VO2 at the nanoscale. We have used STM to map the band structure of the topological materials Sb and SmB6. We have incorporated a molecular beam epitaxy (MBE) system to create novel heterostructures and tailor their properties using atomic resolution feedback from in situ STM.

Topological surface modes in the topological Kondo insulator candidate SmB6

The interplay between strong electron interactions and band topology is a new frontier in the search for exotic quantum phases.