38 research outputs found
Where to find lossless metals?
Hypothetical metals having optical absorption losses as low as those of the
transparent insulators, if found, could revolutionize optoelectronics. We
perform the first high-throughput search for lossless metals among all known
inorganic materials in the databases of over 100,000 entries. The 381
candidates are identified -- having well-isolated partially-filled bands -- and
are analyzed by defining the figures of merit and classifying their real-space
conductive connectivity. The existing experimental evidence of most candidates
being insulating, instead of conducting, is due to the limitation of current
density functional theory in predicting narrow-band metals that are unstable
against magnetism, structural distortion, or electron-electron interactions. We
propose future research directions including conductive oxides, intercalating
layered materials, and compressing these false-metal candidates under high
pressures into eventual lossless metals.Comment: 36 pages, 86 figures, 3 tabl
Fermi-arc diversity on surface terminations of the magnetic Weyl semimetal Co3Sn2S2
Bulk-surface correspondence in Weyl semimetals assures the formation of
topological "Fermi-arc" surface bands whose existence is guaranteed by bulk
Weyl nodes. By investigating three distinct surface terminations of the
ferromagnetic semimetal Co3Sn2S2 we verify spectroscopically its classification
as a time reversal symmetry broken Weyl semimetal. We show that the distinct
surface potentials imposed by three different terminations modify the Fermi-arc
contour and Weyl node connectivity. On the Sn surface we identify
intra-Brillouin zone Weyl node connectivity of Fermi-arcs, while on Co
termination the connectivity is across adjacent Brillouin zones. On the S
surface Fermi-arcs overlap with non-topological bulk and surface states that
ambiguate their connectivity and obscure their exact identification. By these
we resolve the topologically protected electronic properties of a Weyl
semimetal and its unprotected ones that can be manipulated and engineered