Unique Dirac and Triple point fermiology in simple transition metals and their binary alloys
19 Mar 2020
•
Mondal Chiranjit
•
Barman Chanchal K.
•
Sarkar Shuvam
•
Barman Sudipta Roy
•
Alam Aftab
•
Pathak Biswarup
Noble metal surfaces (Au, Ag and Cu etc.) have been extensively studied for
the Shockley type surface states (SSs)...Very recently, some of these Shockley
SSs have been understood from the topological consideration, with the knowledge
of global properties of electronic structure. In this letter, we show the
existence of Dirac like excitations in the elemental noble metal Ru, Re and Os
based on symmetry analysis and first principle calculations. The unique SSs
driven Fermi arcs have been investigated in details for these metals. Our
calculated SSs and Fermi arcs are consistent with the previous transport and
photo-emission results. We attribute these Dirac excitation mediated Fermi arc
topology to be the possible reasons behind several existing transport
anomalies, such as large non-saturating magneto resistance, anomalous Nernst
electromotive force and its giant oscillations, magnetic breakdown etc. We
further show that the Dirac like excitations in these elemental metal can
further be tuned to three component Fermionic excitations, using symmetry
allowed alloy mechanism.(read more)