Three-dimensional disordered conductors in a strong magnetic field: surface states and quantum Hall plateaus

TL;DR

This paper explores the phase diagram of 3D layered conductors under strong magnetic fields, revealing insulator, metal, and quantized Hall phases, with surface states playing a key role in transport.

Contribution

It introduces a new directed network model to describe surface states at a critical point in 3D disordered conductors under magnetic fields.

Findings

Identification of three distinct phases: insulator, metal, and quantized Hall conductor.

Surface states enable transport in the quantized Hall phase.

Development of a novel network model for surface state criticality.

Abstract

We study localization in layered, three-dimensional conductors in strong magnetic fields. We demonstrate the existence of three phases - insulator, metal and quantized Hall conductor - in the two-dimensional parameter space obtained by varying the Fermi energy and the interlayer coupling strength. Transport in the quantized Hall conductor occurs via extended surface states. These surface states constitute a subsystem at a novel critical point, which we describe using a new, directed network model.