AVS 58th Annual International Symposium and Exhibition
    Actinides and Rare Earths Focus Topic Wednesday Sessions
       Session AC+MI-WeA

Invited Paper AC+MI-WeA3
Anomalous Quasiparticle Dynamics in the Hidden Order state of URu2Si2

Wednesday, November 2, 2011, 2:40 pm, Room 209

Session: Magnetic and Electron Correlation Effects in Actinides and Rare Earths
Presenter: Tomasz Durakiewicz, Los Alamos National Lab
Authors: T. Durakiewicz, Los Alamos National Lab
G.L. Dakovski, Los Alamos National Lab
Y. Li, Los Alamos National Lab
S.M. Gilbertson, Los Alamos National Lab
G. Rodriguez, Los Alamos National Lab
A.V. Balatsky, Los Alamos National Lab
J.X. Zhu, Los Alamos National Lab
K. Gofryk, Los Alamos National Lab
E.D. Bauer, Los Alamos National Lab
P.H. Tobash, Los Alamos National Lab
A. Taylor, Los Alamos National Lab
J.L. Sarrao, Los Alamos National Lab
P.M. Oppeneer, Uppsala Univ., Sweden
P.S. Riseborough, Temple Univ.
J.A. Mydosh, Leiden Univ., the Netherlands
Correspondent: Click to Email
An exotic phase of unknown nature emerges from a heavy fermion state in URu2Si2 at T0 = 17.5 K. The nature of this hidden order (HO) state is being vigorously debated, while the massive removal of entropy due to the HO transition evades explanation. Here we use time-and angle-resolved photoemission spectroscopy (tr-ARPES) to elucidate the itinerant nature of HO. We show how the Fermi surface is renormalized by shifting states away from the Fermi level at specific hot spots. By measuring the ultrafast dynamics we identify the location and lifetime of the quasiparticle states forming at the hotspots. We find that the quasiparticle lifetime increases from 42 fs to few hundred fs across the HO transition, and the hidden order parameter is related to the anisotropic gapping of the Fermi surface.