Topological semimetals: surface transport and spin effects
E.V. Deviatov
Osipyan Institute of Solid State Physics, Russian Academy of Sciences, Akademika Osip'yana str. 2, Chernogolovka, Moscow Region, 142432, Russian Federation
For the solid state physics, recent interest to topological systems is mostly connected with topological
semimetals, in particular, to Weyl ones as the most representative semimetal type. Like other
topological materials, e.g. topological and Chern insulators, topological semimetals acquire
topologically protected surface states with linear dispersion. In contrast to helical surface states in
topological insulators, the surface states are chiral for Weyl semimetals, similarly to Chern insulators,
which allows to consider Weyl semimetals as the three-dimensional analog of the quantum Hall effect
regime. Weyl semimetals are also interesting for spin-dependent effects, due to the spin-momentum
locking in the topological surface states. For topological semimetals, the main problem of transport
investigations is to reveal the surface states contribution in the material with gapless bulk spectrum.
Here, we present review of experimental results on charge and spin transport in topological semimetals:
charge transport in different superconducting proximity devices; spin-dependent transport; magnetic
response of the topological surface states; non-linear anomalous Hall effect as the direct manifestation
of the non-zero Berry curvature in topological semimetals. Possible applications are also considered
for this new class of topological materials.
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