Rapid Suppression of the Energy Gap and the Possibility of a Gapless Hidden Order State in URu<sub>2-x</sub>Re<sub>x</sub>Si<sub>2</sub>

ORAL

Abstract

We investigated the energy gap associated with the hidden order (HO) phase and the Gruneisen ratio in the URu2-xRexSi2system using a combination of thermal expansion coefficient and specific heat measurements. As the HO phase transition is suppressed to lower temperature, the ratio between the energy gap and the HO transition temperature decreases by three-fold. This rapid suppression of the energy gap potentially leads to a scenario of a "gapless" HO state, in which the energy gap of the HO phase vanishes before the HO transition temperature is suppressed to 0 K. We also investigated the Gruneisen ratio in the vicinity of the Re substituent composition where the HO is suppressed. The Gruneisen ratio shows divergent behavior at x = 0.12 and 0.15, providing evidence for the existence of a quantum critical point, which is consistent with our hypothesis of a "gapless" HO state.
Research at UCSD was supported by DOE under Grant No. DEFG02-04-ER46105, NSF under Grant No. DMR 1206553, and NNSA through DOE under Grant No. DE-NA0002909.

*The work at Occidental College was supported by the NSF under Grant No.~DMR-1408598. The work at KSU was supported by the NSF under Grant No.~DMR-1505826.

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Presenters

  • Sheng Ran

    • Department of Physics, University of California, San Diego
    • Univ of California - San Diego
    • Physics, University of California, San Diego
    • Department of Physics, Univeristy of Maryland
    • Department of Physics, University of Maryland

Authors

  • Sheng Ran

    • Department of Physics, University of California, San Diego
    • Univ of California - San Diego
    • Physics, University of California, San Diego
    • Department of Physics, Univeristy of Maryland
    • Department of Physics, University of Maryland

  • George Schmiedeshoff

    • Department of Physics, Occidental College

  • Naveen Pouse

    • Department of Physics, University of California, San Diego
    • Department of Physics and Center for Advanced Nanoscience, University of California, San Diego
    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego

  • Inho Jeon

    • University of California, San Diego
    • Physics, University of California, San Diego
    • Department of Physics, University of California, San Diego
    • Materials Science and Engineering, University of California, San Diego
    • Materials Science and Engineering Program and Center for Advanced Nanoscience, University of California, San Diego
    • Materials Science and Engineering Program, and Center for Advanced Nanoscience, Univ of California - San Diego
    • Materials Science and Engineering Program, Univ of California - San Diego
    • University of California-San Diego

  • Nicholas Butch

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron Research
    • NIST- Natl Inst of Stds & Tech
    • Center for Neutron Research, NIST -Natl Inst of Stds & Tech
    • NIST -Natl Inst of Stds & Tech
    • NIST center for neutron research
    • NIST

  • Ram Adhikari

    • Department of Physics, Kent State University
    • Kent State University

  • Carmen Almasan

    • Kent State
    • Department of Physics, Kent State University
    • Kent State University

  • M Brian Maple

    • Department of Physics, University of California, San Diego
    • University of California, San Diego
    • Physics, University of California, San Diego
    • Univ of California - San Diego
    • Department of Physics and Center for Advanced Nanoscience, University of California, San Diego
    • Department of Physics, Center for Advanced Nanoscience,Materials Science and Engineering Program , Univ of California - San Diego
    • Department of Physics, University of California San Diego
    • Physics, Univ of California - San Diego
    • University of California-San Diego
    • UC San Diego
    • Physics, UC San Diego