Topological Phase Transitions in Line-nodal Superconductors

TL;DR

This paper explores the complex interplay between symmetry and topology in line-nodal superconductors, revealing novel phase transition behaviors and experimental signatures that challenge traditional theories.

Contribution

It uncovers a new universality class in topological phase transitions of line-nodal superconductors, highlighting hyper-scaling violation and emergent relativistic scaling.

Findings

Identification of a new universality class in topological phase transitions.

Prediction of a linear phase boundary in temperature-tuning phase diagrams.

Observation of large quantum critical regions due to interplay effects.

Abstract

Fathoming interplay between symmetry and topology of many-electron wave-functions has deepened understanding of quantum many body systems, especially after the discovery of topological insulators. Topology of electron wave-functions enforces and protects emergent gapless excitations, and symmetry is intrinsically tied to the topological protection in a certain class. Namely, unless the symmetry is broken, the topological nature is intact. We show novel interplay phenomena between symmetry and topology in topological phase transitions associated with line-nodal superconductors. The interplay may induce an exotic universality class in sharp contrast to that of the phenomenological Landau-Ginzburg theory. Hyper-scaling violation and emergent relativistic scaling are main characteristics, and the interplay even induces unusually large quantum critical region. We propose characteristic experimental signatures around the phase transitions in three spatial dimensions, for example, a linear phase boundary in a temperature-tuning parameter phase-diagram.