Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Mott Transition in a Valence-Bond Solid Insulator with a Triangular Lattice

Y. Shimizu, H. Akimoto, H. Tsujii, A. Tajima, and R. Kato
Phys. Rev. Lett. 99, 256403 – Published 19 December 2007
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • ACKNOWLEDGEMENTS
    • References

    Abstract

    We have investigated the Mott transition in a quasi-two-dimensional Mott insulator EtMe3P[Pd(dmit)2]2 with a spin-frustrated triangular-lattice in hydrostatic pressure and magnetic-field [Et and Me denote C2H5 and CH3, respectively, and Pd(dmit)2 (dmit=1,3-dithiole-2-thione-4,5-dithiolate,dithiolate) is an electron-acceptor molecule]. In the pressure-temperature (P−T) phase diagram, a valence-bond solid phase is found to neighbor the superconductor and metal phases at low temperatures. The profile of the phase diagram is common to those of Mott insulators with antiferromagnetic order. In contrast to the antiferromagnetic Mott insulators, the resistivity in the metallic phase exhibits anomalous temperature dependence, ρ=ρ0+AT2.5.

    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Received 11 December 2006

    DOI:https://doi.org/10.1103/PhysRevLett.99.256403

    ©2007 American Physical Society

    Authors & Affiliations

    Y. Shimizu1,*, H. Akimoto1, H. Tsujii1,†, A. Tajima1, and R. Kato2

    • 1RIKEN, Wako, Saitama 351-0198, Japan
    • 2CREST, RIKEN, Wako, Saitama 351-0198, Japan

    • *Present address: Institute for Advanced Research, Nagoya University, Japan.
    • †Present address: Department of Physics, Kanazawa University, Japan.

    Article Text (Subscription Required)

    Click to Expand

    References (Subscription Required)

    Click to Expand
    Issue

    Vol. 99, Iss. 25 — 21 December 2007

    Reuse & Permissions
    Access Options
    Author publication services for translation and copyediting assistance advertisement

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1
      P−T phase diagram of EtMe3P[Pd(dmit)2]2 obtained from resistivity measurements. Open circle: metal-insulator transition or crossover temperatures; solid circle: insulator-metal transition temperatures (averages between the cooling and warming processes); square: VBS transitions; triangle: onset superconducting transitions. The solid and doted lines denote the first-order and second-order transitions, respectively. Inset: the schematic VBS state on the triangular lattice of [Pd(dmit)2]2−.Reuse & Permissions
    • Figure 2
      Figure 2
      Resistivity profile of EtMe3P[Pd(dmit)2]2 in hydrostatic pressures (a=4.08, b=4.10, c=4.12, and d=4.15  kbar). Inset: temperature dependence of the activation gap obtained as Δ=d(lnρ)/d(1/T).Reuse & Permissions
    • Figure 3
      Figure 3
      Magnetic-field dependence of resistivity at 4.08 kbar for (a) cooling and (b) warming processes. Inset: H−T phase diagram, where solid and open circles are the M−I transition temperatures for cooling and warming processes, and the square is the transition point of the field sweep measurement.Reuse & Permissions
    • Figure 4
      Figure 4
      Magnetoresistivity measured at 4.2 K and 4.08 kbar for zero-field-cooling (ZFC) and field-cooling (FC) at 16 T.Reuse & Permissions
    • Figure 5
      Figure 5
      Resistivity plotted as a function of T2.5 in the metallic state. The inset shows a log(ρ−ρ0) vs logT plot at pressures below 30 K.Reuse & Permissions
    ×

    Sign up to receive regular email alerts from Physical Review Letters

    Log In

    Cancel
    ×

    Search

    Article Lookup

    Paste a citation or DOI
    Enter a citation
    ×