New three-dimensional dispersion in the type-II Dirac semimetals PtTe\(_2\) and PdTe\(_2\) revealed through Angle Resolved Photoemission Spectroscopy

PtTe\(_2\) and PdTe\(_2\) are among the first transition metal dichalcogenides that were predicted to host type-II Dirac fermions, exotic particles prohibited in free space. These materials are layered and air-stable, which makes them top candidates for technological applications that take advantage...

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Published in:arXiv.org 2024-05
Main Authors: Pelayo, Ivan, Bergner, Derek, Williams, Archibald J, Jiayuwen Qi, Zhu, Penghao, Nabi, Mahfuzun, Huey, Warren L B, Moreschini, Luca, Deng, Ziling, Denlinger, Jonathan, Lanzara, Alessandra, Yuan-Ming, Lu, Windl, Wolfgang, Goldberger, Joshua, Ojeda-Aristizabal, Claudia
Format: Article
Language:English
Subjects:
Chalcogenides
Circular polarization
Crystallography
Density functional theory
Dichroism
Dispersions
Electronic structure
Fermions
Magnetic properties
Mathematical analysis
Photoelectric emission
Polarized light
Spectrum analysis
Topology
Transition metal compounds
Transport properties
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Summary:PtTe\(_2\) and PdTe\(_2\) are among the first transition metal dichalcogenides that were predicted to host type-II Dirac fermions, exotic particles prohibited in free space. These materials are layered and air-stable, which makes them top candidates for technological applications that take advantage of their anisotropic magnetotransport properties. Here, we provide a detailed characterization of the electronic structure of PtTe\(_2\) and PdTe\(_2\) using Angle Resolved Photoemission Spectroscopy (ARPES) and Density Functional Theory (DFT) calculations, unveiling a new three-dimensional dispersion in these materials. Through the use of circularly polarized light, we report a different behavior of such dispersion in PdTe\(_2\) compared to PtTe\(_2\), that we relate to a symmetry analysis of the dipole matrix element. Such analysis reveals a link between the observed circular dichroism and the different momentum-dependent terms in the dispersion of these two compounds, despite their close similarity in crystal structure. Additionally, our data shows a clear difference in the circular dichroic signal for the type-II Dirac cones characteristic of these materials, compared to their topologically protected surface states. Our work provides a useful reference for the ARPES characterization of other transition metal dichalcogenides with topological properties and illustrates the use of circular dichroism as a guide to identify the topological character of two otherwise equivalent band dispersions, and to recognize different attributes in the band structure of similar materials.
ISSN:2331-8422