Metal-insulator transition in pyrochlore Eu2Ir2O7 studied by infrared spectroscopy

ORAL

Abstract

The large family of pyrochlores with formula A$_2$B$_2$C$_7$ attracted a lot of early attention due to strong geometric magnetic frustration. Recent band structure calculations predict that the iridate pyrochlores A$_2$Ir$_2$O$_7$ may have nontrivial topological states. We will report the results of an infrared spectroscopic study of the metal-insulator transition in Eu$_2$Ir$_2$O$_7$ single crystal and Y$_2$Ir$_2$O$_7$ polycrystal. We will report the broad band IR reflection as a function of temperature for an overview of the M-I transition and the low frequency transmission which is more sensitive for detection of a 10 meV gap[1] and other possible excitations. We will discuss possible implications of the semimetal Weyl states. [1] J.J. Ishikawa et al., Phys. Rev. B 85, 245109 (2012).

*Work supported in part by NSF-MRSEC grant DMR-0520471

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Authors

  • Andrei Sushkov

    • Department of Physics, University of Maryland (Physics-UMD)
    • University of Maryland
    • CNAM and MRSEC, Department of Physics, University of Maryland, USA
    • CNAM-UMD

  • Dennis Drew

    • CNAM and MRSEC, Department of Physics, University of Maryland, USA

  • Jun Ishikawa

    • Institute for Solid State Physics, University of Tokyo, Japan

  • Satoru Nakatsuji

    • Institute for Solid State Physics, University of Tokyo, Japan

  • Xuan Luo

    • POSTECH, Korea

  • Sang-Wook Cheong

    • RCEM, Rutgers University, USA