Landau level spectroscopy in current solid state physics

TL;DR

Landau level spectroscopy is a crucial experimental technique in condensed matter physics for probing electronic properties and band structures of various materials using magnetic fields.

Contribution

This review summarizes the fundamentals of Landau level spectroscopy and highlights recent applications in novel materials like graphene and topological systems.

Findings

Enables precise measurement of effective mass and carrier density.

Provides insights into electron-quasiparticle interactions.

Extends to emergent systems with narrow or zero band gaps.

Abstract

Landau level spectroscopy plays an important role in modern condensed-matter physics. In this technique, electrons in a solid are subjected to quantizing magnetic fields and probed experimentally, often through optical methods. Direct and detailed insights into the electronic properties of crystalline materials are obtained, particularly the properties related to their band structure. Landau level spectroscopy enables the precise extraction of key parameters such as effective mass, carrier density, mobility, and band gap, and serves as a powerful tool for studying interactions between electrons and other quasiparticles in solids. Over its more than seventy-year history, Landau level spectroscopy has been applied mainly to semiconductors and semimetals. Today, its scope also includes graphene-based systems, surface and bulk states in topological materials, and other emergent systems with a narrow or vanishing band gap. In this work, we review the fundamentals of Landau level spectroscopy and illustrate them with selected examples from the literature.