Mesoscopic electron focusing in topological insulators

Abstract

The particle wave duality sets a fundamental correspondence between optics and quantum mechanics. Within this framework, the propagation of quasiparticles can give rise to superposition phenomena which, like for electromagnetic waves, can be described by the Huygens principle. However, the utilization of this principle by means of propagation and manipulation of quantum information is limited by the required coherence in time and space. Here we show that in topological insulators, which in their pristine form are characterized by opposite propagation directions for the two quasiparticles spin channels, mesoscopic focusing of coherent charge density oscillations can be obtained at large nested segments of constant energy contours by magnetic surface doping. Our findings provide evidence of strongly anisotropic Dirac fermion-mediated interactions. Even more remarkably, the validity of our findings goes beyond topological insulators but applies for systems with spin orbit lifted degeneracy in general. It demonstrates how spin information can be transmitted over long distances, allowing the design of experiments and devices based on coherent quantum effects in this fascinating class of materials.

References in corpus (6)

• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Quantum Phase Extraction in Isospectral Electronic Nanostructures
• Signatures of Dirac fermion-mediated magnetic order
• Stationary phase approximation approach to the quasiparticle interference on the surface of a strong topological insulator
• Intra- and Interband Electron Scattering in the Complex Hybrid Topological Insulator Bismuth Bilayer on Bi${}_2$Se${}_3$

Cited by in corpus (8)

• Universal response of the type-II Weyl semimetals phase diagram
• Impurity screening and stability of Fermi arcs against Coulomband magnetic scattering in a Weyl monopnictide
• Velocity-determined anisotropic behaviors of RKKY interaction in 8-\textit{Pmmn} borophene
• The AiiDA-KKR plugin and its application to high-throughput impurity embedding into a topological insulator
• Magnetic warping in topological insulators
• Ab-initio Theory of Fourier-transformed Quasiparticle Interference Maps and Application to the Topological Insulator Bi${}_2$Te${}_3$
• Experimental demonstration of a magnetically induced warping transition in a topological insulator mediated by rare-earth surface dopants
• The focusing effect of electron flow and negative refraction in three dimensional topological insulators