Commensurability oscillations in the Hall resistance of unidirectional lateral superlattices

TL;DR

This paper reports the experimental detection of small commensurability oscillations in the Hall resistance of a unidirectional lateral superlattice, comparing results with theory and discussing implications for thermoelectric power.

Contribution

First direct measurement of commensurability oscillations in Hall resistance of ULSL, revealing smaller amplitudes than theoretical predictions.

Findings

CO observed in Hall resistance with small amplitude (~1 Ω)

Measured CO are significantly smaller than theoretical predictions

Discussion on implications for thermoelectric power of ULSL

Abstract

We have observed commensurability oscillations (CO) in the Hall resistance $R_{yx}$ of a unidirectional lateral superlattice (ULSL). The CO, having small amplitudes ($\sim$ 1 $\Omega$) and being superposed on a roughly three-orders of magnitude larger background, are obtained by directly detecting the difference in $R_{yx}$ between the ULSL area and the adjacent unmodulated two-dimensional electron gas area, and then extracting the odd part with respect to the magnetic field. The CO thus obtained are compared with a theoretical calculation and turn out to have the amplitude much smaller than the theoretical prediction. The implication of the smaller-than-predicted CO in $R_{yx}$ on the thermoelectric power of ULSL is briefly discussed.