title: Visualizing the formation of the Kondo lattice and the hidden order in URu(2)Si(2).
abstract: Heavy electronic states originating from the f atomic orbitals underlie a rich variety of quantum phases of matter. We use atomic scale imaging and spectroscopy with the scanning tunneling microscope to examine the novel electronic states that emerge from the uranium f states in URu(2)Si(2). We find that, as the temperature is lowered, partial screening of the f electrons' spins gives rise to a spatially modulated Kondo-Fano resonance that is maximal between the surface U atoms. At T = 17.5 K, URu(2)Si(2) is known to undergo a second-order phase transition from the Kondo lattice state into a phase with a hidden order parameter. From tunneling spectroscopy, we identify a spatially modulated, bias-asymmetric energy gap with a mean-field temperature dependence that develops in the hidden order state. Spectroscopic imaging further reveals a spatial correlation between the hidden order gap and the Kondo resonance, suggesting that the two phenomena involve the same electronic states.
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Pegor
authors.initials: P
authors.lastname: Aynajian
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: da Silva Neto
authors.forename: Colin V
authors.initials: CV
authors.lastname: Parker
authors.forename: Yingkai
authors.initials: Y
authors.lastname: Huang
authors.forename: Abhay
authors.initials: A
authors.lastname: Pasupathy
authors.forename: John
authors.initials: J
authors.lastname: Mydosh
authors.forename: Ali
authors.initials: A
authors.lastname: Yazdani