Electronic structure of the hidden-order transition in URu2Si2
DIPC Seminars
- Speaker
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Andres Santander-Syro, Université Paris-Sud, France
- When
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2019/07/17
14:00 - Place
- Donostia International Physics Center
- Add to calendar
-
iCal
Due to their exceptionally strong correlations, f-electron systems present a
wide realm of original phase transitions and often poorly understood states of
matter. One of the most intriguing is the so-called hidden-order (HO) state
forming below THO =17.5 K in URu2Si2. Extensive macroscopic characterizations
gathered during the last 30 years show a reduction of almost 60% in the
electronic specific heat across the transition, and suggest that a gap of
about 10 meV opens over more than a half of its Fermi surface. However, the
identification of the associated broken symmetry and gap structure are still a
riddle [1-3].
Following our observation of a Fermi-surface instability occurring at the
hidden-order transition in URu2Si2 [4], we recently studied, using state-of-
the art angle-resolved photoemission spectroscopy, the associated changes in
its electronic structure [8, 9]. I will show how these data provide a unified
microscopic picture of the large entropy loss, gap opening and Fermi-surface
reconstruction inferred from thermodynamic and magneto-transport measurements
in URu2Si2. I will also describe our recent studies of a quantum-critical
transitions in doped URu2Si2, leading to disappearance of the hidden-order
state and the onset of long-range antiferromagnetism.
[1] T. M. Palstra et al. Superconducting and magnetic transitions in the
heavy-fermion system URu2Si2. Phys Rev Lett. 55, 2727-2730 (1985).
[2] M. B. Maple et al. Partially gapped Fermi surface in the heavy-electron
superconductor URu2Si2. Phys. Rev. Lett. 56, 185-188 (1986).
[3] J. A. Mydosh and P. M. Oppeneer. Colloquium: Hidden order,
superconductivity, and magnetism: The unsolved case of URu2Si2. Rev. Mod.
Phys. 83, 1301 (2011).
[4] A. F. Santander-Syro et al. Fermi-surface instability at the ’hidden-
order’ transition of URu2Si2. Nature Phys. 5, 637-641 (2009).
[5] F. L. Boariu et al. Momentum-resolved evolution of the Kondo lattice into
“hidden-order†in URu2Si2. Phys. Rev. Lett. 110, 156404 (2013).
[6] C. Bareille et al. Momentum-resolved “hidden-order†gap structure,
symmetries, and entropy loss in URu2Si2. Nature Commun. 5, 4326 (2014).
Host: Enrique Ortega