Imaging the Formation of High-Energy Dispersion Anomalies in the ActinideUCoGa5
Tanmoy Das, Tomasz Durakiewicz, Jian-Xin Zhu, John J. Joyce, John L. Sarrao, Matthias J. Graf
Physical Review X
We use angle-resolved photoemission spectroscopy (ARPES) to image the emergence of substaintial dispersion anomalies in the electronic renormalization of the actinide compound UCoGa_5 which was presumed to belong to a conventional Fermi liquid family. Kinks or abrupt breaks in the slope of the quasiparticle dispersion are detected both at low (∼130 meV) and high (∼1 eV) binding energies below the Fermi energy, ruling out any significant contribution of phonons. We perform numerical calculations
... to demonstrate that the anomalies are adequately described by coupling between itinerant fermions and spin fluctuations arising from the particle-hole continuum of the spin-orbit split 5f states of uranium. These anomalies are resemble the 'waterfall' phenomenon of the high-temperature copper-oxide superconductors, suggesting that spin fluctuations are a generic route toward multiform electronic phases in correlated materials as different as high-temperature superconductors and actinides.