SPECIAL SEMINAR: Through the looking glass and back: characterizing exotic states by simple invariants

A main thrust of condensed matter physics concerns the discovery of new electronic states in emerging materials.  One example is the rapidly expanding class of topological materials, which exhibit novel transport behavior such as conductance quantization.  Topology characterizes fundamental properties of shapes, ignoring factors such as size or local deformations, which makes topological electronic states unusually robust.  We will tell the story of how exotic phenomena can arise from the interplay of ferromagnetism and topology in relativistic materials and how these novel phases can be harnessed to build the next generation of quantum devices.  I will lay out a suite of complementary tools – electronic transport, nanofabrication, and microwave impedance microscopy (MIM) – that shed light on topological electronic states across the phase diagram in two systems: bilayer graphene and magnetic topological insulators.  Finally, I will outline how MIM could be used in the future to visualize and manipulate Majorana modes, an emerging platform for quantum information processing.

 

Bio: Monica Allen is a Karel Urbanek Postdoctoral Fellow in the Applied Physics Department at Stanford University.  Her research aims to combine scanning probe microscopy with transport techniques to spatially visualize electronic phases in quantum materials and utilize them for emerging technologies, such as quantum information processing.  Monica completed her B.A. and Ph.D. in Physics at Harvard University, where she integrated nanofabrication and quantum transport measurements to investigate low-dimensional phenomena in graphene.  Her graduate research was funded by the Office of Science Graduate Fellowship, awarded by the U.S. Department of Energy.