Nonsymmorphic Weyl superconductivity in UPt_3 based on E_2u representation

TL;DR

This paper demonstrates that UPt_3 is a topological Weyl superconductor with tunable Weyl nodes, unusual gap structures, and topological surface states, based on a nonsymmorphic symmetry-adapted E_2u order parameter.

Contribution

It introduces a theoretical framework showing UPt_3 as a Weyl superconductor with symmetry-protected nodes and topological features, clarifying experimental observations.

Findings

UPt_3 hosts tunable Weyl nodes in its superconducting phase.

The model explains the coexistence of point and line nodes consistent with experiments.

Nonsymmorphic symmetry protects arc nodes on the Brillouin zone face.

Abstract

We show that a heavy fermion superconductor UPt_3 is a topological Weyl superconductor with tunable Weyl nodes. Adopting a generic order parameter in the E_2u representation allowed by nonsymmorphic crystal symmetry, we clarify unusual gap structure and associated topological properties. The pair creation, pair annihilation, and coalescence of Weyl nodes are demonstrated in the time-reversal symmetry broken B-phase. At most 98 point nodes compatible with Blount's theorem give rise to line node-like behaviors in low-energy excitations, consistent with experimental results. We also show an arc node protected by the nonsymmorphic crystal symmetry on the Brillouin zone face.