Classical effects in the weak-field magnetoresistance of InGaAs/InAlAs quantum wells

TL;DR

This study investigates the unusual low-temperature magnetoresistance in high-mobility InGaAs/InAlAs quantum wells, revealing classical effects due to surface ridges that influence electron motion beyond quantum corrections.

Contribution

It demonstrates that classical effects, specifically electron motion along open orbits caused by surface ridges, explain the magnetoresistance behavior in these quantum wells.

Findings

Magnetoresistance exceeds quantum correction scales.

Classical effects account for observed magnetoresistance.

Surface ridges induce open orbits affecting electron transport.

Abstract

We observe an unusual behavior of the low-temperature magnetoresistance of the high-mobility two-dimensional electron gas in InGaAs/InAlAs quantum wells in weak perpendicular magnetic fields. The observed magnetoresistance is qualitatively similar to that expected for the weak localization and anti-localization but its quantity exceeds significantly the scale of the quantum corrections. The calculations show that the obtained data can be explained by the classical effects in electron motion along the open orbits in a quasiperiodic potential relief manifested by the presence of ridges on the quantum well surface.