New class of small amplitude low-field magnetoresistance oscillation in unidirectional lateral superlattice: Geometric resonance of Bragg-reflected cyclotron orbit

TL;DR

This paper reports a newly observed small amplitude magnetoresistance oscillation in unidirectional lateral superlattices at low magnetic fields, attributed to geometric resonance of cyclotron orbits reflected by Bragg scattering.

Contribution

It introduces a new class of low-field magnetoresistance oscillation linked to Bragg-reflected cyclotron orbits in unidirectional superlattices, expanding understanding of electron behavior in such structures.

Findings

Oscillation observed at |B| <= 0.03 T

Oscillation maxima shift with electron concentration and superlattice period

Attributed to commensurability of a and open orbit widths

Abstract

We have uncovered a new class of small amplitude magnetoresistance oscillation in unidirectional lateral superlattice (ULSL). The oscillation is observed in a low-field regime, typically |B| =< 0.03 T, as small undulation on top of well-known positive magnetoresistance background. Positions of maxima of the oscillation shift to lower field side with the increase of the electron concentration n_e roughly proportionally to n_e^{-1/2}, and also with the increase of period a of ULSL samples. The oscillation is attributed to commensurability between the period a and the width of open orbits originating from the miniband structure.