Transport studies of a bent quantum Hall junction at integer filling factor ν show strongly insulating states (ν=1,2) at higher fields. In this paper we analyze the strongly insulating behavior as a function of temperature T and dc bias Vdc in order to classify the localization mechanisms responsible for the insulating state. The temperature dependence suggests a crossover from activated nearest-neighbor hopping at higher T to variable-range hopping conduction G∼exp [- (T0 T) 1/2] at lower T. The base temperature electric-field dependence shows I (E) ∼exp [- (E0 E) 1/2], consistent with one-dimensional (1D) variable-range hopping conduction. We observe almost identical behavior at ν=1 and ν=2, and discuss how the bent quantum Hall junction conductance appears to be independent of the bulk spin state. Various models of 1D variable-range hopping, which either include or ignore interactions are compared all of which are consistent with the basic model of disorder coupled counterpropagating quantum Hall edges.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jun 23 2008|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics