Electric field driven quantum phase transition between band insulator and topological insulator

TL;DR

This paper theoretically shows that an electric field can induce a quantum phase transition from a band insulator to a topological insulator in CdTe/HgCdTe/CdTe quantum wells, enabling electrical control of topological phases.

Contribution

It introduces a method to manipulate the quantum phase of HgTe quantum wells using electric fields, with detailed phase diagrams considering temperature effects.

Findings

Electric field can switch the topological insulator phase on or off.

Temperature significantly influences the phase diagram.

Electric control offers an efficient way to manipulate quantum phases.

Abstract

We demonstrate theoretically that electric field can drive a quantum phase transition between band insulator to topological insulator in CdTe/HgCdTe/CdTe quantum wells. The numerical results suggest that the electric field could be used as a switch to turn on or off the topological insulator phase, and temperature can affect significantly the phase diagram for different gate voltage and compositions. Our theoretical results provide us an efficient way to manipulate the quantum phase of HgTe quantum wells.