Formation of the Coherent Heavy Fermion Liquid at the Hidden Order Transition inURu2Si2

Abstract

In this article we present high-resolution angle-resolved photoemission (ARPES) spectra of the heavy-fermion superconductor URu2Si2. Measurements as a function of both excitation energy and temperature allow us to disentangle a variety of spectral features, revealing the evolution of the low energy electronic structure across the hidden order transition. Already above the hidden order transition our measurements reveal the existence of weakly dispersive states below the Fermi level that exhibit a large scattering rate. Upon entering the hidden order phase, these states transform into a coherent heavy fermion liquid that hybridizes with the conduction bands.

Momentum-resolved hidden-order gap reveals symmetry breaking and origin of entropy loss in URu2Si2

“…This naturally explains the abrupt increase in the electron lifetime below T HO observed by previous thermal transport and ARPES experiments 14,30 , and studied in detail in another recent ARPES work 31 .…”

Optical study of hybridization and hidden order in URu2Si2

“…In Nd 0.905 TiO 3 , 1/⌧ (⌦, T ) scales as ⌦ 2 up to about 0.1 eV, followed by a maximum at ⇡ 0.27 eV. The ⌦ = 0 intercept of 1/⌧ scales as T 2 over a wide temperature range: from 29 to 295 K. 25 In Ce 0.095 Ca 0.05 TiO 3.04 , 1/⌧ (⌦, T ) scales as ⌦ 2 also up to about 0.1 eV, followed by a tendency to saturation; but the maximum is not yet revealed at the highest frequency measured (⇡ 0.14 eV). The ⌦ = 0 intercept also scales as T 2 over a wide range of temperatures.…”

Symmetry and correlations underlying hidden order inURu2Si2

“…There have been many attempts to reconcile firstprinciples calculations 29,[47][48][49] with experimental angleresolved photoemission spectrum (ARPES) 26,47,[50][51][52][53] . A crucial detail is the location of Fermi surface (FS) pockets.…”