Induced robust topological order on an ordinary insulator hetero-structured with a strong topological insulator

TL;DR

This paper demonstrates that a topological surface state can be induced in an ordinary insulator through heterostructuring with a strong topological insulator, revealing a new way to manipulate topological phases.

Contribution

It reports the first observation of a Dirac cone topological surface state induced in an ordinary insulator via heterostructure with a strong topological insulator.

Findings

Induced topological surface state observed in Sb2Se3 layer up to 15 nm thick.

No topological surface state observed in OI/OI heterostructures.

Heterostructuring enables manipulation of topological states in ordinary insulators.

Abstract

Topological states of matter originate from distinct topological electronic structures of materials. As for strong topological insulators (STIs), the topological surface (interface) is a direct consequence of electronic structure transition between materials categorized to different topological genus. Therefore, it is fundamentally interesting if such topological character can be manipulated. Besides tuning the crystal field and the strength of spin-orbital coupling (e.g., by external strain, or chemical doping), there is currently rare report on topological state induced in ordinary insulators (OIs) by the heterostructure of OI/STI. Here we report the observation of a Dirac cone topological surface state (TSS) induced on the Sb2Se3 layer up to 15 nm thick in the OI/STI heterostructure, in sharp contrast with the OI/OI heterostructure where no sign of TSS can be observed. This is evident for an induced topological state in an OI by heterostructure.