Quantum oscillations in the noncentrosymmetric superconductor and topological nodal-line semimetal PbTaSe_2

摘要

We observed quantum oscillations in thermoelectric and magnetic torque signals in noncentrosymmetric superconductor PbTaSe2. One oscillatory frequency stems from the orbits formed by magnetic breakdown, while others are from two-dimensional-like Fermi surfaces near the topological nodal rings. Our comprehensive understanding of the Fermi surface topology of PbTaSe2, including nailing down the Fermi level and detecting the Berry phases near the nodal rings, is crucial for searching plausible topological superconductivity in its bulk and surface states.