Fermi-crossing Type-II Dirac fermions and topological surface states in NiTe2

DOI: 10.1038/s41598-020-69926-8

Authors: Saumya Mukherjee (Diamond Light Source; University of Oxford) , Sung Won Jung (Diamond Light Source) , Sophie F. Weber (University of California; Lawrence Berkeley National Laboratory) , Chunqiang Xu (University of Technology) , Dong Qian (Shanghai Jiao Tong University) , Xiaofeng Xu (Zhejiang University of Technology) , Pabitra K. Biswas (ISIS Facility) , Timur K. Kim (Diamond Light Source) , Laurent C. Chapon (Diamond Light Source) , Matthew D. Watson (Diamond Light Source) , Jeffrey B. Neaton (University of California; Lawrence Berkeley National Laboratory; Kavli Energy Nanosciences Institute) , Cephise Cacho (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 10

State: Published (Approved)
Published: July 2020
Diamond Proposal Number(s): 21591

Abstract: Transition-metal dichalcogenides (TMDs) offer an ideal platform to experimentally realize Dirac fermions. However, typically these exotic quasiparticles are located far away from the Fermi level, limiting the contribution of Dirac-like carriers to the transport properties. Here we show that NiTe2 hosts both bulk Type-II Dirac points and topological surface states. The underlying mechanism is shared with other TMDs and based on the generic topological character of the Te p-orbital manifold. However, unique to NiTe2, a significant contribution of Ni d orbital states shifts the energy of the Type-II Dirac point close to the Fermi level. In addition, one of the topological surface states intersects the Fermi energy and exhibits a remarkably large spin splitting of 120 meV. Our results establish NiTe2 as an exciting candidate for next-generation spintronics devices.

Journal Keywords: Electronic properties and materials; Topological insulators

Diamond Keywords: Spintronics

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Added On: 03/08/2020 12:55

Documents:
s41598-020-69926-8.pdf

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Physics Electronics Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES) High Resolution ARPES (HR-ARPES)