Zhanzhi Jiang, UT-Austin

"Imaging topological edge states in two-dimensional electron systems"

Abstract: The last decade has witnessed the rise of the "Topological Era" in condensed matter physics with discovery of diverse topological phases and materials. The "Quantum Hall Family" - quantum Hall (QH) state, quantum spin Hall (QSH) state and quantum anomalous hall (QAH) state - characterized by 2D insulating bulk states and 1D topologically protected edge states, are particularly attractive as promising building blocks for dissipationless transistors and fault-tolerant quantum computers. However, the spatial landscape of edge and bulk conduction of these states is largely unexplored. Using microwave impedance microscopy (MIM), we have obtained preliminary results on the dissipationless edge states in a candidate QSH system, InAs/GaInSb quantum well, and the suppression of bulk-edge contrast under moderate magnetic fields. We have also started the construction of a dilution-refrigerator-based MIM system to systematically study QAH states in magnet-doped Bi2(Se,Te)3 thin films.