# Magneto-optical Signatures of Volkov-Pankratov States in Topological Insulators

## TL;DR

This paper theoretically investigates the magneto-optical response of Volkov-Pankratov states at topological insulator interfaces, revealing distinctive signatures that enable their identification under magnetic fields.

## Contribution

It provides a theoretical analysis of the magneto-optical signatures of massive surface states, highlighting their distinguishability from bulk states in topological insulators.

## Key findings

- Volkov-Pankratov states exhibit unique magneto-optical responses.
- Magnetic field orientation affects the detectability of these states.
- Distinct signatures allow experimental identification of massive surface states.

## Abstract

In addition to the usual chiral surface states, massive surface states can arise at a smooth interface between a topological and a trivial bulk insulator. While not subject to topological protection as the chiral states, these massive states, theorized by Volkov and Pankratov in the 1980s, reflect nevertheless emergent Dirac physics at the interface. We study theoretically the magneto-optical response of these surface states, which is strikingly different from that of the bulk states. Most saliently, we show that these states can be identified clearly in the presence of a magnetic field and its orientation with respect to the interface.