English

Berezinskii-Kosterlitz-Thouless transition in the type-I Weyl semimetal PtBi$_2$

Superconductivity 2024-06-12 v2 Mesoscale and Nanoscale Physics Materials Science

Abstract

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_2 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 Tc275400T_c \sim 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 TBKT310T_\text{BKT} \sim 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_2 an ideal platform to study low dimensional and unconventional superconductivity in topological semimetals.

Keywords

Cite

@article{arxiv.2101.01620,
  title  = {Berezinskii-Kosterlitz-Thouless transition in the type-I Weyl semimetal PtBi$_2$},
  author = {Arthur Veyrat and Valentin Labracherie and Dima L. Bashlakov and Federico Caglieris and Jorge I. Facio and Grigory Shipunov and Titouan Charvin and Rohith Acharya and Yurii Naidyuk and Romain Giraud and Jeroen van den Brink and Bernd Büchner and Christian Hess and Saicharan Aswartham and Joseph Dufouleur},
  journal= {arXiv preprint arXiv:2101.01620},
  year   = {2024}
}

Comments

to be published in Nano Letters