title: Correlation between ground state and orbital anisotropy in heavy fermion materials.
abstract: The interplay of structural, orbital, charge, and spin degrees of freedom is at the heart of many emergent phenomena, including superconductivity. Unraveling the underlying forces of such novel phases is a great challenge because it not only requires understanding each of these degrees of freedom, it also involves accounting for the interplay between them. Cerium-based heavy fermion compounds are an ideal playground for investigating these interdependencies, and we present evidence for a correlation between orbital anisotropy and the ground states in a representative family of materials. We have measured the 4f crystal-electric field ground-state wave functions of the strongly correlated materials CeRh1-xIrxIn5 with great accuracy using linear polarization-dependent soft X-ray absorption spectroscopy. These measurements show that these wave functions correlate with the ground-state properties of the substitution series, which covers long-range antiferromagnetic order, unconventional superconductivity, and coexistence of these two states.
authors: Institute of Physics II, University of Cologne, 50937 Cologne, Germany;
authors: Thomas
authors: T
authors: Willers
authors: Institute of Physics II, University of Cologne, 50937 Cologne, Germany;
authors: Fabio
authors: F
authors: Strigari
authors: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany;
authors: Zhiwei
authors: Z
authors: Hu
authors: European Synchrotron Radiation Facility, 38043 Grenoble Cédex, France;
authors: Violetta
authors: V
authors: Sessi
authors: European Synchrotron Radiation Facility, 38043 Grenoble Cédex, France;
authors: Nicholas B
authors: NB
authors: Brookes
authors: Los Alamos National Laboratory, Los Alamos, NM 87545; and.
authors: Eric D
authors: ED
authors: Bauer
authors: Los Alamos National Laboratory, Los Alamos, NM 87545; and.
authors: John L
authors: JL
authors: Sarrao
authors: Los Alamos National Laboratory, Los Alamos, NM 87545; and.
authors: J D
authors: JD
authors: Thompson
authors: Department of Quantum Matter, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan.
authors: Arata
authors: A
authors: Tanaka
authors: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany;
authors: Steffen
authors: S
authors: Wirth
authors: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany;
authors: Liu Hao
authors: LH
authors: Tjeng
authors: Institute of Physics II, University of Cologne, 50937 Cologne, Germany; severing@ph2.uni-koeln.de.
authors: Andrea
authors: A
authors: Severing
keywords: X-ray absorption; crystal fields; heavy fermions; rare earth