Kondo hybridization and enigmatic <i>f</i>-quasiparticles emerging from deep within the antiferromagnetic phase of USb<sub>2</sub>

ORAL

Abstract

Novel electronic phenomena frequently form in heavy fermion systems because of the f-electrons’ localized and itinerant nature. When magnetically ordered, the f moments are expected to be frozen and localized, decoupled from the Fermi surface. It remains ambiguous whether a Kondo-lattice can emerge from deep inside the magnetic phase or simply breaks down below TN. Using spectroscopic imaging with the scanning tunneling microscope complemented by neutron scattering, we probe the electronic states in the antiferromagnetic USb2 as a function of temperature. We visualize an antiferromagnetic gap at high temperatures (T<TN~200K) in which Kondo hybridization gradually develops below Tcoh~80K near the Fermi energy. At T*=45K we find an electronic transition through the abrupt emergence of non-trivial sharp 5f quasiparticles, whose appearance agrees with the sudden release of entropy seen in specific heat. Our findings demonstrate the emergence of Kondo physics from inside USb2's antiferromagnetic phase, spectroscopically establishing the dual nature of f-electrons, and reveal an enigmatic electronic transition, which may share connection with the ‘hidden order’ phase of URu2Si2.

*We acknowledge support from the U.S. National Science Foundation (NSF) CAREER under award No. DMR-1654482.

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Presenters

  • Ioannis Giannakis

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton
    • Binghamton University

Authors

  • Ioannis Giannakis

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton
    • Binghamton University

  • Justin Leshen

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton
    • Binghamton University

  • Mariam Kavai

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton
    • Binghamton University

  • Sheng Ran

    • University of Maryland, College Park
    • Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland

  • Shanta Saha

    • Physics, University of Maryland
    • Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland
    • University of Maryland, College Park & NIST
    • Department of Physics, University of Maryland, College Park
    • University of Maryland
    • University of Maryland - College Park

  • Nicholas Butch

    • Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland

  • Pegor Aynajian

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton
    • Binghamton University