4 research outputs found
Non-local signatures of the chiral magnetic effect in Dirac semimetal BiSb
The field of topological materials science has recently been focussing on
three-dimensional Dirac semimetals, which exhibit robust Dirac phases in the
bulk. However, the absence of characteristic surface states in accidental Dirac
semimetals (DSM) makes it difficult to experimentally verify claims about the
topological nature using commonly used surface-sensitive techniques. The chiral
magnetic effect (CME), which originates from the Weyl nodes, causes an
-dependent chiral charge polarization, which
manifests itself as negative magnetoresistance. We exploit the extended
lifetime of the chirally polarized charge and study the CME through both local
and non-local measurements in Hall bar structures fabricated from single
crystalline flakes of the DSM BiSb. From the non-local
measurement results we find a chiral charge relaxation time which is over one
order of magnitude larger than the Drude transport lifetime, underlining the
topological nature of BiSb.Comment: 6 pages, 6 figures + 7 pages of supplemental materia
periodic Andreev bound states in a Dirac semimetal
Electrons in a Dirac semimetals possess linear dispersion in all three
spatial dimensions, and form part of a developing platform of novel quantum
materials. BiSb supports a three-dimensional Dirac cone at the
Sb-induced band inversion point. Nanoscale phase-sensitive junction technology
is used to induce superconductivity in this Dirac semimetal. Radio frequency
irradiation experiments reveal a significant contribution of 4-periodic
Andreev bound states to the supercurrent in Nb-BiSb-Nb
Josephson junctions. The conditions for a substantial contribution to
the supercurrent are favourable because of the Dirac cone's topological
protection against backscattering, providing very broad transmission
resonances. The large g-factor of the Zeeman effect from a magnetic field
applied in the plane of the junction, allows tuning of the Josephson junctions
from 0 to regimes.Comment: Supplementary information is include