Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides

DOI: 10.1038/nmat5031

Authors: M. S. Bahramy (University of Tokyo; RIKEN center for Emergent Matter Science (CEMS)) , O. J. Clark (University of St Andrews) , B.-J. Yang (Seoul National University; Institute for Basic Science (IBS), Seoul) , J. Feng (University of St Andrews; Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) CAS) , L. Bawden (University of St Andrews) , J. M. Riley (University of St Andrews; Diamond Light Source) , I. Markovic (University of St Andrews; Max Planck Institute for Chemical Physics of Solids) , F. Mazzola (SUPA, University of St Andrews) , V. Sunko (SUPA, University of St Andrews; Max Planck Institute for Chemical Physics of Solids) , D. Biswas (University of St Andrews) , S. P. Cooil (University of Science and Technology) , M. Jorge (University of Science and Technology) , J. W. Wells (University of Science and Technology) , M. Leandersson (MAX IV Laboratory, Lund University) , T. Balasubramanian (MAX IV Laboratory, Lund University) , J. Fujii (Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC) , I. Vobornik (Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC) , J. E. Rault (Synchrotron Soleil) , T. K. Kim (Diamond Light Source) , M. Hoesch (Diamond Light Source) , K. Okawa (Tokyo Institute of Technology) , M. Asakawa (Tokyo Institute of Technology) , T. Sasagawa (Tokyo Institute of Technology) , T. Eknapakul (Suranaree University of Technology) , W. Meevasana (Suranaree University of Technology; ThEP, Commission of Higher Education, Bangkok) , P. D. C. King (University of St Andrews)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Materials , VOL 17 , PAGES 21

State: Published (Approved)
Published: November 2017
Diamond Proposal Number(s): 2469 , 9500 , 13438 , 14927

Abstract: Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.

Journal Keywords: Electronic properties and materials; Surfaces, interfaces and thin films; Topological insulators

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Other Facilities: Elettra; SOLEIL; Max-Lab

Added On: 30/11/2017 15:20

Discipline Tags:

Surfaces Quantum Materials Hard condensed matter - electronic properties Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)