6 research outputs found
Bereziskii-Kosterlitz-Thouless transition in the Weyl system \ce{PtBi2}
Symmetry breaking in topological matter became, in the last decade, a key
concept in condensed matter physics to unveil novel electronic states. In this
work, we reveal that broken inversion symmetry and strong spin-orbit coupling
in trigonal \ce{PtBi2} lead to a Weyl semimetal band structure, with unusually
robust two-dimensional superconductivity in thin fims. Transport measurements
show that high-quality \ce{PtBi2} crystals are three-dimensional
superconductors (600~mK) with an isotropic critical field
(50~mT). Remarkably, we evidence in a rather thick flake
(60~nm), exfoliated from a macroscopic crystal, the two-dimensional nature of
the superconducting state, with a critical temperature ~mK and highly-anisotropic critical fields. Our results reveal a
Berezinskii-Kosterlitz-Thouless transition with ~mK and
with a broadening of Tc due to inhomogenities in the sample. Due to the very
long superconducting coherence length in \ce{PtBi2}, the
vortex-antivortex pairing mechanism can be studied in unusually-thick samples
(at least five times thicker than for any other two-dimensional
superconductor), making \ce{PtBi2} an ideal platform to study low dimensional
superconductivity in a topological semimetal
Transition Bereziskii-Kosterlitz-Thouless dans des nanostructures du semimétal de Weyl \ce{PtBi2}
Symmetry breaking in topological matter became, in the last decade, a key concept in condensed matter physics to unveil novel electronic states. In this work, we reveal that broken inversion symmetry and strong spin-orbit coupling in trigonal \ce{PtBi2} lead to a Weyl semimetal band structure, with unusually robust two-dimensional superconductivity in thin fims. Transport measurements show that high-quality \ce{PtBi2} crystals are three-dimensional superconductors (600~mK) with an isotropic critical field (50~mT). Remarkably, we evidence in a rather thick flake (60~nm), exfoliated from a macroscopic crystal, the two-dimensional nature of the superconducting state, with a critical temperature ~mK and highly-anisotropic critical fields. Our results reveal a Berezinskii-Kosterlitz-Thouless transition with ~mK and with a broadening of Tc due to inhomogenities in the sample. Due to the very long superconducting coherence length in \ce{PtBi2}, the vortex-antivortex pairing mechanism can be studied in unusually-thick samples (at least five times thicker than for any other two-dimensional superconductor), making \ce{PtBi2} an ideal platform to study low dimensional superconductivity in a topological semimetal
Transition Bereziskii-Kosterlitz-Thouless dans des nanostructures du semimétal de Weyl \ce{PtBi2}
Symmetry breaking in topological matter became, in the last decade, a key concept in condensed matter physics to unveil novel electronic states. In this work, we reveal that broken inversion symmetry and strong spin-orbit coupling in trigonal \ce{PtBi2} lead to a Weyl semimetal band structure, with unusually robust two-dimensional superconductivity in thin fims. Transport measurements show that high-quality \ce{PtBi2} crystals are three-dimensional superconductors (600~mK) with an isotropic critical field (50~mT). Remarkably, we evidence in a rather thick flake (60~nm), exfoliated from a macroscopic crystal, the two-dimensional nature of the superconducting state, with a critical temperature ~mK and highly-anisotropic critical fields. Our results reveal a Berezinskii-Kosterlitz-Thouless transition with ~mK and with a broadening of Tc due to inhomogenities in the sample. Due to the very long superconducting coherence length in \ce{PtBi2}, the vortex-antivortex pairing mechanism can be studied in unusually-thick samples (at least five times thicker than for any other two-dimensional superconductor), making \ce{PtBi2} an ideal platform to study low dimensional superconductivity in a topological semimetal
Berezinskii–Kosterlitz–Thouless Transition in the Type‑I Weyl Semimetal PtBi<sub>2</sub>
Symmetry breaking in topological matter has become in
recent years
a key concept in condensed matter physics to unveil novel electronic
states. In this work, we predict that broken inversion symmetry and
strong spin–orbit coupling in trigonal PtBi2 lead
to a type-I Weyl semimetal band structure. Transport measurements
show an unusually robust low dimensional superconductivity in thin
exfoliated flakes up to 126 nm in thickness (with Tc ∼ 275–400 mK), which constitutes the first
report and study of unambiguous superconductivity in a type-I Weyl
semimetal. Remarkably, a Berezinskii-Kosterlitz-Thouless transition
with TBKT ∼ 310 mK is revealed
in up to 60 nm thick flakes, which is nearly an order of magnitude
thicker than the rare examples of two-dimensional superconductors
exhibiting such a transition. This makes PtBi2 an ideal
platform to study low dimensional and unconventional superconductivity
in topological semimetals