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

Type-I superconductivity in the Dirac semimetal PdTe2

H. Leng, C. Paulsen, Y. K. Huang, and A. de Visser
Phys. Rev. B 96, 220506(R) – Published 20 December 2017
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • ACKNOWLEDGMENTS
    • Supplemental Material
    References

    Abstract

    The superconductor PdTe2 was recently classified as a type-II Dirac semimetal, and advocated to be an improved platform for topological superconductivity. Here, we report magnetic and transport measurements conducted to determine the nature of the superconducting phase. Surprisingly, we find that PdTe2 is a type-I superconductor with Tc=1.64 K and a critical field μ0Hc(0)=13.6 mT. Our crystals also exhibit the intermediate state as demonstrated by the differential paramagnetic effect. For H>Hc we observe superconductivity of the surface sheath. This calls for a close examination of superconductivity in PdTe2 in view of the presence of topological surface states.

    • Figure
    • Figure
    • Figure
    • Figure
    • Received 10 October 2017
    • Revised 4 December 2017

    DOI:https://doi.org/10.1103/PhysRevB.96.220506

    ©2017 American Physical Society

    Physics Subject Headings (PhySH)

    1. Research Areas
    Electrical propertiesMeissner effectSuperconducting phase transition
    1. Physical Systems
    Dirac semimetalLow-temperature superconductorsType-I superconductors
    Condensed Matter, Materials & Applied Physics

    Authors & Affiliations

    H. Leng1,*, C. Paulsen2, Y. K. Huang1, and A. de Visser1,†

    • 1Van der Waals–Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
    • 2Institut Néel, CNRS & Université Grenoble Alpes, BP 166, 38042 Grenoble Cedex 9, France

    • *h.leng@uva.nl
    • †a.devisser@uva.nl

    Article Text (Subscription Required)

    Click to Expand

    Supplemental Material (Subscription Required)

    Click to Expand

    References (Subscription Required)

    Click to Expand
    Issue

    Vol. 96, Iss. 22 — 1 December 2017

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

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1

      dc magnetization per unit volume (SI units) as a function of applied field for PdTe2 at temperatures from 0.31 K (right) to 1.50 K (left), as indicated. The initial slope χm=dM/dHa accounts for a superconducting sample volume of 100% with N=0.12 (dashed line). The dashed-dotted line indicates the idealized M(Ha) curve with slope 1/N in the intermediate state at T=0.31 K. The black arrow indicates Hc at T=0.31 K. The red arrow points to a kink and start of a tail in M(Ha). Inset: Zoom of the kink feature at a few selected temperatures.

      Reuse & Permissions
    • Figure 2
      Figure 2

      dc susceptibility M/Ha (in SI units) as a function of temperature in fields μ0Ha from 1 mT (right) to 10 mT (left) in steps of 1 mT. Data are taken after cooling in zero field (ZFC) and field cooled (FC) as shown by the arrows. Inset: Part of the ZFC-FC curves in applied fields of 0.2 (red), 0.1 (blue), and 0.05 mT (green).

      Reuse & Permissions
    • Figure 3
      Figure 3

      ac susceptibility of PdTe2. Upper panels (a) and (b): In-phase and out-of-phase component of the ac susceptibility for an ac driving field μ0Hac=0.25 mT. Data are taken in dc fields μ0Ha=0–10 mT, as indicated. The large peaks in χac′ when a dc field is applied are due to the differential paramagnetic effect. Lower panels: ac susceptibility in a small ac driving field μ0Hac=0.0005mT. (c) As a function of temperature at dc fields from 0 to 14 mT, as indicated. (d) As a function of applied field at a temperature of 0.31 K, and from 0.40 to 1.50 K in steps of 0.1 K.

      Reuse & Permissions
    • Figure 4
      Figure 4

      Superconducting phase diagram of PdTe2 for Ha∥a axis. Bulk superconductivity is found below Hc(T) as determined by dc magnetization and χac′. The red line represents a fit to Hc(T)=Hc(0)[1−(T/Tc)2], with μ0Hc(0)=13.6 mT and Tc=1.64 K. Surface superconductivity is found below Hcs(T) as determined by χac′ for a small amplitude of Hac (see text). The green line represents a fit to Hcs(T)=Hcs(0)[1−(T/Tcs)2], with μ0Hcs(0)=34.9 mT and Tcs=1.33 K. The blue symbols denote HcR(T) and are taken from the superconducting transition measured by resistance. The blue line compares HcR(T) with the WHH model curve (see text).

      Reuse & Permissions
    ×

    Sign up to receive regular email alerts from Physical Review B

    Log In

    Cancel
    ×

    Search

    Article Lookup

    Paste a citation or DOI
    Enter a citation
    ×