Topological states and phase transitions in Sb${}_2$Te${}_3$-GeTe multilayers

Abstract

Topological insulators (TIs) are bulk insulators with exotic 'topologically protected' surface conducting modes. It has recently been pointed out that when stacked together, interactions between surface modes can induce diverse phases including the TI, Dirac semimetal, and Weyl semimetal. However, currently a full experimental understanding of the conditions under which topological modes interact is lacking. Here, working with multilayers of the TI Sb${}_2$Te${}_3$ and the band insulator GeTe, we provide experimental evidence of a multiple topological modes in a single Sb${}_2$Te${}_3$-GeTe-Sb${}_2$Te${}_3$ structure. Furthermore, we show that reducing the thickness of the GeTe layer induces a phase transition from a Dirac-like phase to a gapped phase. By comparing different multilayer structures we demonstrate that this transition occurs due to the hybridisation of states associated with different TI films. Our results demonstrate that the Sb${}_2$Te${}_3$-GeTe system offers strong potential towards manipulating topological states as well as towards controlledly inducing various topological phases.

Scientific reports (accepted)

References in corpus (16)

• Topological Insulators
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Weyl Semimetal in a Topological Insulator Multilayer
• Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Non-saturating magnetoresistance in heavily disordered semiconductors
• Bulk Band Gap and Surface State Conduction Observed in Voltage-Tuned Crystals of the Topological Insulator Bi${}_2$Se${}_3$
• Competition between weak localization and antilocalization in topological surface states
• Two-dimensional Transport Induced Linear Magneto-Resistance in Topological Insulator Bi${}_2$Se${}_3$ Nanoribbons
• Landau quantization and the thickness limit of topological insulator thin films of Sb2Te3
• Stacked topological insulator built from bismuth-based graphene sheet analogues
• Manipulation of Topological States and Bulk Band Gap Using Natural Heterostructures of a Topological Insulator
• Topological insulating behaviour in conducting property of crystalline Ge-Sb-Te
• Magnetotransport and induced superconductivity in Bi based three-dimensional topological insulators
• A new superconductor derived from topological insulator heterostructure
• Designer Topological Insulators in Superlattices

Cited by in corpus (6)

• Comparative study of Weyl semimetal, topological and Chern insulators: thin-film point of view
• Disentangling surface and bulk transport in topological-insulator $p$-$n$ junctions
• Long-lived non-equilibrium superconductivity in a non-centrosymmetric Rashba semiconductor
• Thickness dependence of electron-electron interactions in topological p-n junctions
• Probing embedded topological modes in bulk-like GeTe-Sb${}_2$Te${}_3$ heterostructures
• Chirality relaxation in low-temperature strongly Rashba-coupled systems