AVS 65th International Symposium & Exhibition
    Actinides and Rare Earths Focus Topic Thursday Sessions
       Session AC-ThA

Invited Paper AC-ThA8
Hundess, Coherence and Magnetism in URu2Si2- and USb2-family Materials

Thursday, October 25, 2018, 4:40 pm, Room 202C

Session: Early Career Scientists
Presenter: L. Andrew Wray, New York University
Authors: L.A. Wray, New York University
L. Miao, New York University
H. He, New York University
S. Ran, University of Maryland, College Park
N.P. Butch, Nist / Umd
J.D. Denlinger, Advanced Light Source, Lawrence Berkeley National Laboratory
Y.-D. Chuang, Advanced Light Source, Lawrence Berkeley National Laboratory
Correspondent: Click to Email
The uranium compounds URu2Si2 and USb2 present fascinating low temperature phase diagrams, and are focal points of long-standing debates regarding how the crossover between strong correlations and electronic itinerancy should be conceptualized and evaluated. It has recently been found that uranium O-edge resonant X-ray spectroscopies can help to image this multi-natured wavefunction by providing a fingerprint of the f-electron atomic multiplet states. I will present a systematic O-edge spectroscopic characterization of URu2Si2 and USb2 as a function of doping, and show that these data align well with a “Hund’s metal” picture for both compounds. Distinct differences in the degree of “Hundess” (same-atom alignment of electron magnetic moments) as a function of chemical composition are found to underlie important features of the low temperature phase diagrams, such as the transition from a “hidden order” phase to antiferromagnetism, and the loss of a low temperature coherence feature in transport measurements. Based on these results, I will propose that developing a more quantitative experimental characterization of Hundness in many-body wavefunctions is of fundamental importance to the broader goal of understanding the phase diagrams in metallic systems with non-trivial local moment physics.