Engineering a spin-orbit bandgap in graphene-tellurium heterostructures

Intensive research has focused on harnessing the potential of graphene for electronic, optoelectronic, and spintronic devices by generating a bandgap at the Dirac point and enhancing spin-orbit interaction. While proximity to heavy p elements is promising, their interaction in graphene heterostructu...

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Authors: Cano Muñiz, Beatriz, Calleja, Fabián, Pacilè, Daniela, Cuxart, Marc G., Pisarra, Michele, Sindona, Antonello, Martín García, Fernando, Salagre, Elena, Segovia Cabrero, María Pilar, García Michel, Enrique, López Vázquez de Parga, Amadeo, Miranda Soriano, Rodolfo, Camarero de Diego, Julio, Garnica, Manuela, Valbuena, Miguel Angel
Format: article
Publication Date:2025
Country:España
Institution:Universidad Autónoma de Madrid
Repository:Biblos-e Archivo. Repositorio Institucional de la UAM
Language:English
OAI Identifier:oai:dnet:biblosearchi::a9bbac7d9bcb108a508c153ff9bdd2e0
Online Access:https://hdl.handle.net/10486/758260
https://dx.doi.org/10.1002/adfm.202425154
Access Level:Open access
Keyword:Angle-resolved photoemission spectroscopy
bandgap opening
graphene heterostructures
scanning tunneling microscopy
spin-orbit coupling
Física
Química
Description
Summary:Intensive research has focused on harnessing the potential of graphene for electronic, optoelectronic, and spintronic devices by generating a bandgap at the Dirac point and enhancing spin-orbit interaction. While proximity to heavy p elements is promising, their interaction in graphene heterostructures remains underexplored compared to ferromagnetic, noble, or heavy metals. This study demonstrates the effective intercalation of Te atoms in a graphene/Ir(111) heterostructure. Using low-energy electron diffraction and scanning tunneling microscopy, two distinct structural phases are identified as a function of Te coverage. Angle-resolved photoemission spectroscopy reveals a 240 meV bandgap at the Dirac cone at room temperature, preserving linear dispersion, along with a pronounced n-doping effect confirmed by quasiparticle interference maps. Notably, reducing Te coverage tunes the Dirac point toward the Fermi level while maintaining the bandgap. Spin-resolved measurements uncover a non-planar chiral spin texture with significant splitting in both in-plane and out-of-plane components, as well as evidence of an emerging edge state from scanning tunneling spectroscopy. These findings highlight Te-enhanced intrinsic spin-orbit coupling in graphene, surpassing the extrinsic Rashba effect and promoting a spin-orbit-induced bandgap. This system offers a promising platform for spin-dependent transport phenomena, such as the quantum spin Hall effect