Evidence from tunneling spectroscopy for a quasi-one-dimensional origin of superconductivity in Sr2RuO4
Abstract
To establish the mechanism of unconventional superconductivity in Sr2RuO4, a prerequisite is direct information concerning the momentum-space structure of the energy gaps Delta(i) (k), and in particular whether the pairing strength is stronger ("dominant") on the quasi-one-dimensional (alpha and beta) or on the quasi-two-dimensional (gamma) Fermi surfaces. We present scanning tunneling microscopy measurements of the density of states spectra in the superconducting state of Sr2RuO4 for 0.1T(c) < T < T-c and analyze them along with published thermodynamic data using a simple phenomenological model. We show that our observation of a single superconducting gap scale with maximum value 2 Delta approximate to 5T(c) along with a spectral shape indicative of line nodes is consistent, within a weak-coupling model, with magnetically mediated odd-parity superconductivity generated by dominant, near-nodal, Cooper pairing on the alpha and beta bands.
Citation
Firmo , I A , Lederer , S , Lupien , C , Mackenzie , A P , Davis , J C & Kivelson , S A 2013 , ' Evidence from tunneling spectroscopy for a quasi-one-dimensional origin of superconductivity in Sr 2 RuO 4 ' , Physical Review. B, Condensed matter and materials physics , vol. 88 , no. 13 , 134521 . https://doi.org/10.1103/PhysRevB.88.134521
Publication
Physical Review. B, Condensed matter and materials physics
Status
Peer reviewed
ISSN
1098-0121Type
Journal article
Description
Funding: UK EPSRC and Royal Society-Wolfson Research Merit Award.Collections
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