Sculpting the electrostatic landscape in quantum materials

Abstract:
The electrostatic landscape in low-dimensional materials can be controlled by engineering the external environment. External charges near the material can produce hills and valleys of potential energy that modify the properties of the material. In some applications, we seek quantum materials with an ultra-smooth electrostatic landscape, while other applications require periodic superlattices, or steps in potential energy, or traveling waves of electrostatic potential. In this talk, I will present recent experiments on carbon nanotubes, graphene, and 2D semiconductors where we use a variety of techniques to sculpt the electrostatic landscape: free-standing materials (surrounded by vacuum), materials encapsulated in boron nitride, dual-gated materials, and materials coupled to piezoelectric surface acoustic waves. We recently employed these techniques to investigate (i) field-induced dissociation of strongly bound excitons, (ii) gate-controlled hybridization of the valley pseudo-spin degree of freedom, and (iii) steps towards realizing a Thouless pump for electrons (a topologically-protected pump for electrons).

Bio:
Ethan Minot is a Professor in the Department of Physics at Oregon State University. Ethan holds a Ph.D. Physics from Cornell University, and B.S. in Physics from Massey University. His research investigates questions related to nanoscale systems such as carbon nanotubes and graphene. The broader impact of his work ranges from solar energy harvesting to medicine. Current investigations include photocurrent generation in carbon nanotubes, quantum phases in 1d materials, and the development of graphene biosensors for neuroscience applications.