Magnetic Exciton Mediated Superconductivity in the Hidden-Order Phase of URu2Si2

TL;DR

This paper proposes that magnetic excitons mediate superconductivity in URu2Si2's hidden-order phase, explaining experimental observations and predicting chiral d-wave pairing with anisotropic critical fields.

Contribution

It introduces a magnetic exciton mechanism for superconductivity in URu2Si2, linking collective excitations to the hidden-order phase and unconventional pairing symmetry.

Findings

Magnetic excitons are linked to the hidden-order phase.

Superconductivity is suppressed in high-pressure antiferromagnetic phase.

Chiral d-wave singlet pairing is predicted based on exciton momentum dependence.

Abstract

We propose the magnetic exciton mediated superconductivity occurring in the enigmatic hidden-order phase of URu2Si2. The characteristic of the massive collective excitation observed only in the hidden-order phase is well reproduced by the antiferro hexadecapole ordering model as the trace of the dispersive crystalline-electric-field excitation. The disappearance of the superconductivity in the high-pressure antiferro magnetic phase can naturally be understood by the sudden suppression of the magnetic-exciton intensity. The analysis of the momentum dependence of the magnetic-exciton mode leads to the exotic chiral d-wave singlet pairing in the Eg symmetry. The Ising-like magnetic-field response of the mode yields the strong anisotropy observed in the upper critical field even for the rather isotropic 3-dimensional Fermi surfaces of this compound.