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arXiv · 1401.2108

Observation of Time-Reversal Symmetry Breaking in the Non-Centrosymmetric Superconductor Re6Zr

R. P. Singh·A. D. Hillier·B. Mazidian·J. Quintanilla·J. F. Annett·D. McK. Paul·G. Balakrishnan·M. R. Lees
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Abstract

We have investigated the superconducting state of the non-centrosymmetric compound Re6Zr using magnetization, heat capacity, and muon-spin relaxation/rotation (muSR) measurements. Re6Zr has a superconducting transition temperature, Tc = 6.75 K. Transverse-field muSR experiments, used to probe the superfluid density, suggest an s-wave character for the superconducting gap. However, zero and longitudinal-field muSR data reveal the presence of spontaneous static magnetic fields below Tc indicating that time-reversal symmetry is broken in the superconducting state and an unconventional pairing mechanism. An analysis of the pairing symmetries identifies the ground states compatible with time-reversal symmetry breaking.

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R. P. Singh, A. D. Hillier, B. Mazidian, J. Quintanilla, J. F. Annett, D. McK. Paul, G. Balakrishnan, M. R. Lees. 2014-03-10. Observation of Time-Reversal Symmetry Breaking in the Non-Centrosymmetric Superconductor Re6Zr. https://doi.org/10.1103/physrevlett.112.107002

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