Photoemission investigations of URu₂Si₂

Abstract

A brief review of selected experimental photoemission works on URu₂Si₂ spanning almost 25 years is presented. We focus on the areas of importance for both the paramagnetic (PM) and hidden-order (HO) phases, where photoemission provides direct and strong evidence for: (i) f–d hybridization, (ii) presence of hybridization gap, (iii) details of the massive reconstruction of FS upon transition and (iv) a non-integer valence likely close to 2.6. While most of the FS reconstruction details have been mapped and are now known, the most recent high resolution and low temperature ARPES studies reveal novel electronic structure features related to HO. No single ARPES experiment so far captures all of the phases appearing in this system as temperature is lowered.

Keywords:

• URu₂Si₂
• hidden order
• photoemission
• ARPES

Acknowledgements

This work was supported by the Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division and LANL LDRD programs.