paper

Unconventional superconducting gap structure protected by space group symmetry

arXiv:1801.03293 · doi:10.1103/PhysRevB.97.134512

Abstract

Recent superconducting gap classifications based on space group symmetry have revealed nontrivial gap structures that were not shown by point group symmetry. First, we review a comprehensive classification of symmetry-protected line nodes within the range of centrosymmetric space groups. Next, we show an additional constraint; line nodes peculiar to nonsymmorphic systems appear only for primitive or orthorhombic base-centered Bravais lattice. Then, we list useful classification tables of 59 primitive or orthorhombic base-centered space groups for the superconducting gap structures. Furthermore, our gap classification reveals the -dependent point nodes (gap opening) appearing on a 3- or 6-fold axis, which means that the presence (absence) of point nodes depends on the Bloch-state angular momentum . We suggest that this unusual gap structure is realized in a heavy-fermion superconductor UPt, using a group-theoretical analysis and a numerical calculation. The calculation demonstrates that a Bloch phase contributes to as effective orbital angular momentum by site permutation. We also discuss superconducting gap structures in MoS, SrPtAs, UBe, and PrOsSb.

18 pages, 9 figures

References in corpus (32)

Cited by in corpus (29)