Time-reversal symmetry breaking in superconductors through loop pair-current order

ORAL

Abstract

We propose a superconducting instability where microscopic loop pair-currents form spontaneously within a unit cell at the critical temperature, Tc . Such currents break time-reversal symmetry (TRS) without needing an unconventional pairing mechanism. Using Ginzburg-Landau theory
we show how they emerge in a toy model and estimate an upper bound for the resulting magnetisation, which is consistent with recent muon-spin relaxation experiments. We discuss the crystal symmetry requirements and show that they are met by the Re6X (X=Zr, Hf, Ti) family of TRS-breaking, but otherwise seemingly conventional, superconductors.

*We acknowledge support from EPSRC (EP/P007392/1, EP/P00749X/1).

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Presenters

  • Sudeep Ghosh

    • School of Physical Sceinces, University of Kent, Canterbury, UK
    • Physics, University of Kent

Authors

  • Sudeep Ghosh

    • School of Physical Sceinces, University of Kent, Canterbury, UK
    • Physics, University of Kent

  • Jorge Quintanilla

    • SPS, University of Kent
    • School of Physical Sceinces, University of Kent, Canterbury, UK
    • Physics, University of Kent
    • University of Kent

  • James Annett

    • H. H. Wills Physics Laboratory, University of Bristol, Bristol, UK
    • Physics, University of Bristol