Hidden order symmetry and superconductivity in URu2Si2 investigated by quasiparticle interference

TL;DR

This study uses quasiparticle interference to differentiate between two leading hidden order models in URu2Si2 and explores how superconductivity signatures can be detected via QPI.

Contribution

The paper demonstrates that QPI spectra can distinguish between rank-4 and rank-5 hidden order models in URu2Si2, providing a microscopic method for identifying the correct order parameter.

Findings

QPI spectrum shows fourfold symmetry breaking in the rank-5 model.

QPI can differentiate between the proposed HO models.

Signature of chiral d-wave superconductivity is identified in QPI.

Abstract

The hidden order (HO) in URu2Si2 has been determined as a high rank multipole formed by itinerant 5f-electrons with distinct orbital structure imposed by the crystalline electric field. Because this can lead to a considerable number of different multipoles it is of great importance to use microscopic techniques that are sensitive to their subtle physical differences. Here we investigate whether quasiparticle interference (QPI) method can distinguish between the two most frequently proposed HO parameter models: the even rank-4 hexadecapole and the odd-rank-5 dotriacontapole model. We obtain the quasiparticle dispersion and reconstructed Fermi surface in each HO phase adapting an effective two-orbital model of 5f bands that reproduces the main Fermi surface sheets of the para phase. We show that the resulting QPI spectrum reflects directly the effect of fourfold symmetry breaking in the rank-5 model which is absent in the rank-4 model. Therefore we suggest that QPI method should give a possibility of direct discrimination between the two most investigated models of HO in URu2Si2. Furthermore the signature of proposed chiral d-wave superconducting (SC) order parameter in QPI of the coexisting HO+SC phase is investigated.