The gating of edge states by ultrashort gates (50 nm) placed on normal quantum Hall effect devices is studied. In longer-gate devices, plateaus in the longitudinal resistance are found when an integer number of edge states is reflected from the gate. The expected quantized values of longitudinal resistance do not appear in the ultrashort gate devices, indicating that tunneling of the edge states through the depletion barrier continuously occurs for biases less than that needed to completely deplete the region near the gate.
ASJC Scopus subject areas
- Condensed Matter Physics