Revisiting Hall coefficient measurements in samarium hexaboride

ORAL

Abstract

Samarium hexaboride is a correlated material in which strong f-d interactions open a small gap at the Fermi energy below ~100 K. In transport, SmB6 demonstrates activated behavior down to ~4 K, terminated by a conduction mechanism attributed to the emergence of a topological surface state. We present a study of transport, especially Hall coefficient, from three perspectives. First, we discuss a method of analyzing Hall data at low temperatures, allowing for accurate extraction of mobility from the conductive surface. Next, we re-examine a well-known high-temperature feature in Hall data: the sign change from negative to positive as temperature is raised above ~65 K. This sign change has been attributed to skew scattering due to the strong f-d interactions, but it leads to an inaccurate determination of carrier density and mobility. We discuss a method to improve the accuracy of transport analysis that relies on ARPES data at high temperature to correct for the positive Hall sign. Finally, we present a method of carving a micron-sized Hall bar from SmB6 to investigate the effect of sample size on transport parameters. Taken together, these results aim to provide a summary of current transport perspectives on SmB6.

*Funding for this work was provided by NSF Grant No. DGE-1256260.

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Presenters

  • Alexa Rakoski

    • Department of Physics, Univ of Michigan - Ann Arbor

Authors

  • Alexa Rakoski

    • Department of Physics, Univ of Michigan - Ann Arbor

  • Yun Suk Eo

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

  • Dmitri Mihaliov

    • Department of Physics, Univ of Michigan - Ann Arbor

  • Cagliyan Kurdak

    • Department of Physics, Univ of Michigan - Ann Arbor

  • Priscila Rosa

    • Los Alamos National Laboratory
    • Los Alamos Natl Lab
    • Los Alamos National Laboratory, USA

  • Zachary Fisk

    • Department of Physics and Astronomy, University of California Irvine
    • Department of Physics and Astronomy, University of California, Irvine
    • Dept. of Physics and Astronomy, University of California Irvine
    • University of California, Irvine, USA
    • Department of Physics and Astronomy,, University of California-Irvine

  • Boyoun Kang

    • Gwangju Institute of Science and Technology

  • Myung-suk Song

    • Gwangju Institute of Science and Technology

  • Beongki Cho

    • Gwangju Institute of Science and Technology

  • Monica Ciomaga Hatnean

    • Department of Physics, University of Warwick

  • Geetha Balakrishnan

    • University of Warwick
    • Department of Physics, University of Warwick
    • Physics, University of Warwick
    • Physics Department, University of Warwick, Coventry, CV4 7AL, United Kingdom