Transition to the quantum hall regime in InAs nanowire cross-junctions

Johannes Gooth,Kornelius Nielsch,Heinz Schmid,Nicolas Bologna,Marta D Rossell,Mattias Borg,Heike Riel,Stephan Wirths,Kirsten Moselund

doi:10.1088/1361-6641/ab0591

Abstract

We present a low-temperature electrical transport study on four-terminal ballistic InAs nanowire cross-junctions in magnetic fields aligned perpendicular to the cross-plane. Two-terminal longitudinal conductance measurements between opposing contact terminals reveal typical 1D conductance quantization at zero magnetic field. As the magnetic field is applied, the 1D bands evolve into hybrid magneto-electric sub-levels that eventually transform into Landau levels for the widest nanowire devices investigated (width = 100 nm). Hall measurements in a four-terminal configuration on these devices show plateaus in the transverse Hall resistance at high magnetic fields that scale with (ve2/h)−1. e is the elementary charge, h denotes Planck’s constant and v is an integer that coincides with the Landau level index determined from the longitudinal conductance measurements. While the 1D conductance quantization in zero magnetic field is fragile against disorder at the NW surface, the plateaus in the Hall resistance at high fields remain robust as expected for a topologically protected Quantum Hall phase.

Highlights

IntroductionSemiconductor nanowire (NW) cross-junctions have recently been considered as one of the means to implement interconnected NW network circuitry [1, 2]
We present a low-temperature electrical transport study on four-terminal ballistic InAs nanowire cross-junctions in magnetic fields aligned perpendicular to the cross-plane
In a first transport experiment, we verify that the InAs nanowire cross-junctions are ballistic 1D quantum wire systems at zero magnetic field

Summary

Introduction

Semiconductor nanowire (NW) cross-junctions have recently been considered as one of the means to implement interconnected NW network circuitry [1, 2] In such a scheme, each NW branch is controlled individually via local gate transistor nodes, giving rise to reconfigurable logic operations. Each NW branch is controlled individually via local gate transistor nodes, giving rise to reconfigurable logic operations Another possible application of NW cross-junction is in quantum computing technology, [3,4,5,6,7] where ballistic cross-junctions enable the transfer of quantum information between qubits.

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Conclusion