Quantum Hall Effect II

3:00 pm – 6:00 pm, Thursday March 20 // Session MAR-T21 //Anaheim Convention Center, 254A (Level 2)

Chair:: Chengyu Wang, Princeton University
Topics:
Sponsored by: DCMP

Edge state dispersion from momentum resolved tunnelling

5:00 pm – 5:12 pm

Presenter: Henok Weldeyesus (University of Basel)

Authors: Taras Patlatiuk (University of Basel), Christian Scheller (University of Basel), Qianqian Chen (University of Basel), Dominik Zumbuhl (University of Basel)

Topological states of matter have attracted much attention in current research, which is intimately tied to the appearance of conducting edge or surface states at the boundaries of these topological insulators. Therefore, methods that enable the study of these edge states can add significant insight into the properties of these topological materials.

Here we present the measurement of Landau level edge state dispersions in the integer quantum Hall effect via momentum resolved tunnelling spectroscopy. By leveraging the structure of GaAs cleaved edge overgrowth double quantum wires adjacent to a 2D electron gas we can study the tunnel current between the edge states and a quantum wire. This tunnelling between parallel 1D systems is both energy and momentum conserving, which enables us to extract the full dispersion via tunnel conductance measurements.

In combination with a simple numerical model describing the edge states in the presence of a hard wall, we can confirm the viability of our measurement technique which opens the door for further measurement on more complicated phases such as the fractional quantum Hall effect.

PRESENTATIONS (15)