2,798 research outputs found
Non-locality of zero-bias anomalies in the topologically-trivial phase of Majorana wires
We show that the topologically trivial zero bias peak (ZBP) emerging in
semiconductor Majorana wires due to soft confinement exhibits correlated
splitting oscillations as a function of the applied Zeeman field, similar to
the correlated splitting of the Majorana ZBP. Also, we find that the presence
of a strong impurity can effectively cut the wire in two and destroy the
correlated splitting in both the trivial and the Majorana regimes. We identify
a strong nonlocal effect that operates only in the topologically trivial regime
and demonstrate that the dependence of the ZBP on the confining gate potential
at the opposite end in Majorana wires with two normal metal end-contacts
represents a powerful tool for discriminating between topologically trivial and
nontrivial ZBPs.Comment: published version, 4+ pages, 4 figure
Topologically protected surface Majorana arcs and bulk Weyl fermions in ferromagnetic superconductors
A number of ferromagnetic superconductors have been recently discovered which
are believed to be in the so-called "equal spin pairing" (ESP) state. In the
ESP state the Cooper pairs condense forming order parameters
which are decoupled
in the spin-sector. We show that these three-dimensional systems should
generically support topologically protected surface Majorana arcs and bulk Weyl
fermions as gapless excitations. Similar protected low-energy exotic
quasiparticles should also appear in the recently discovered
non-centrosymmteric superconductors in the presence of a Zeeman field. The
protected surface arcs can be probed by angle-resolved photoemission (ARPES) as
well as scanning tunneling microscope (STM) experiments.Comment: 5 pages and 2 figures; Figure 2 revised, typos correcte
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