Crossover between magnetic and electric edges in quantum Hall systems

Abstract

We report on the transition from magnetic edge to electric edge transport in a split magnetic gate device which applies a notch magnetic field to a two-dimensional electron gas. The gate bias allows tuning the overlap of magnetic and electric edge wavefunctions on the scale of the magnetic length. Conduction at magnetic edges -in the 2D-bulk -is found to compete with conduction at electric edges until magnetic edges become depleted. Current lines then move to the electrostatic edges as in the conventional quantum Hall picture. The conductivity was modelled using the quantum Boltzmann equation in the exact hybrid potential. The theory predicts the features of the bulk-edge cross-over in good agreement with experiment.

Quantum transport through pairs of edge states of opposite chirality at electric and magnetic boundaries

“…We define h as the thickness of the magnet, d is the distance between the two magnets (split gate)or the width of the magnet (strip gate), z 0 is the depth of the 2DEG and µ 0 M s is the saturation magnetization. As a representative case, we choose some experimentally realizable values as d =200 nm, h=80 nm, z 0 =30 nm and µ 0 M s =2.90 T (Dy) [37].…”

“…The properties of graphene in a non-uniform magnetic field have also attracted attention [25][26][27][28][29][30][31][32][33][34][35][36]. In recent work, magnetoresistance anomaly has been observed in a quantum Hall system due to the controlled interference between magnetic edge states and conventional electrostatic edge states [37].…”

Generation, manipulation and detection of snake state trajectories of a neutral atom in a ring-cavity

“…The first experimental confirmation of such states was carried in a 2DEG realised in GaAs-AlGaAs heterostructure by K. von Klitzing's group [29]. These developments were subsequently followed by a substantial number of theoretical and experimental studies [30][31][32][33][34][35][36][37].…”