Photoemission Imaging of 3D Fermi Surface Pairing at the Hidden Order Transition in URu2Si2

TL;DR

This study uses ARPES to explore the 3D Fermi surface and electron pairing in URu2Si2, revealing itinerant 5f electrons, critical nesting vectors, and FS gapping associated with the hidden order transition.

Contribution

It provides detailed 3D Fermi surface mapping and evidence of electron pairing at the FS, advancing understanding of the hidden order in URu2Si2.

Findings

Full itinerancy of 5f electrons confirmed

Identification of 3D Fermi surface nesting vectors

Detection of FS gapping and pairing in the HO phase

Abstract

We report angle-resolved photoemission spectroscopy (ARPES) experiments probing deep into the hidden order (HO) state of URu2Si2, utilizing tunable photon energies with sufficient energy and momentum resolution to detect the near Fermi surface (FS) behavior. Our results reveal: (i) the full itinerancy of the 5f electrons; (ii) the crucial three-dimensional (3D) k-space nature of the FS and its critical nesting vectors, in good comparison with density-functional theory calculations, and (iii) the existence of hot-spot lines and pairing of states at the FS, leading to FS gapping in the HO phase.