Imaging the Nanoscale Band Structure of Topological Sb

TL;DR

This paper introduces band structure tunneling microscopy (BSTM), a novel nanoscale technique combining Landau level spectroscopy and quasiparticle interference imaging to analyze the complex surface states of topological semimetal antimony (Sb).

Contribution

The study pioneers BSTM, enabling detailed nanoscale analysis of band structures and their deformation, which advances understanding of topological materials for electronic and spintronic applications.

Findings

Reconstructed the multi-component surface state band structure of Sb.

Demonstrated BSTM's ability to probe non-rigid band deformations.

Quantified metrics relevant for spintronics applications.

Abstract

Many promising building blocks of future electronic technology - including non-stoichiometric compounds, strongly correlated oxides, and strained or patterned films - are inhomogeneous on the nanometer length scale. Exploiting the inhomogeneity of such materials to design next-generation nanodevices requires a band structure probe with nanoscale spatial resolution. To address this demand, we report the first simultaneous observation and quantitative reconciliation of two candidate probes - Landau level spectroscopy and quasiparticle interference imaging - which we employ here to reconstruct the multi-component surface state band structure of the topological semimetal antimony(Sb). We thus establish the technique of band structure tunneling microscopy (BSTM), whose unique advantages include nanoscale access to non-rigid band structure deformation, empty state dispersion, and magnetic field dependent states. We use BSTM to elucidate the relationship between bulk conductivity and surface state robustness in topological materials, and to quantify essential metrics for spintronics applications.