Quantum Corrals and Quantum Mirages on the Surface of a Topological Insulator

TL;DR

This paper investigates quantum corrals on topological insulator surfaces, revealing how magnetic and nonmagnetic configurations influence resonance states, spin resolution, quantum mirages, and impurity interactions, with potential applications in spintronics.

Contribution

It introduces the effects of different magnetic configurations on quantum corrals on TI surfaces, including spin-resolved states and quantum mirages, which were not previously explored.

Findings

Spin-resolved energy states in FM corrals.

Quantum mirage of magnetic impurities in FM corrals.

Modulation of magnetic impurity interactions.

Abstract

We study quantum corrals on the surface of a topological insulator (TI). Different resonance states induced by nonmagnetic (NM), antiferromagnetic (AFM), and ferromagnetic (FM) corrals are found. Intriguingly, the spin is clearly energy-resolved in a FM corral, which can be effectively used to operate surface carrier spins of TI. We also show that an observable quantum mirage of a magnetic impurity can be projected from the occupied into the empty focus of a FM elliptic corral, while in NM and AFM corrals the mirage signal becomes negligibly weak. In addition, the modulation of the interaction between two magnetic impurities in the quantum corrals is demonstrated. These prominent effects may be measured by spin-polarized STM experiments.