Fermiology and type-I superconductivity in the chiral superconductor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Nb</mml:mi><mml:msub><mml:mrow><mml:mi>Ge</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math> with Kramers-Weyl fermions
Eve Emmanouilidou, Sougata Mardanya, Jie Xing, P. Venugopal Reddy, Amit Agarwal, Tay‐Rong Chang, Ni Ni
Abstract
NbGe${}_{2}$ is a type-I full-gap bulk chiral superconductor with Kramers-Weyl fermions and an enhanced critical field from filamentary superconductivity. Quantum oscillations and first-principles calculations reveal two hole Fermi pockets centered around the Weyl $M$ point and one trivial hole pocket near the $H$ point in the Brillouin zone. The authors attribute the electron-phonon mediated superconductivity to the Van Hove singularity arising from the saddle-point-like dispersion at the $M$ and $H$ points near the Fermi level.
Topics & Concepts
PhysicsSuperconductivitySaddle pointCondensed matter physicsBrillouin zoneBCS theoryFermionQuantum mechanicsPairingGeometryMathematicsPhysics of Superconductivity and MagnetismSuperconductivity in MgB2 and AlloysIron-based superconductors research