Abstract
Most quantum point contacts (QPCs) fabricated in high-mobility two-dimensional electron gases show a zero-bias conductance peak near pinchoff but the origin of this peak remains a mystery. Previous experiments have primarily focused on the zero-bias peak at moderate conductance, in the range . Here, measurements are presented of zero-bias peaks that persist down to . Magnetic field and temperature dependencies of the zero-bias peak in the low-conductance limit are qualitatively different from the analogous phenomenology at higher conductance with implications for existing theoretical models of transport in low-density QPCs.
- Received 20 May 2010
DOI:https://doi.org/10.1103/PhysRevB.82.045313
©2010 American Physical Society