Normal state 17O NMR studies of Sr2RuO4 under uniaxial stress
Abstract
The effects of uniaxial compressive stress on the normal state 17O nuclear-magnetic-resonance properties of the unconventional superconductor Sr2RuO4 are reported. The paramagnetic shifts of both planar and apical oxygen sites show pronounced anomalies near the nominal a-axis strain ϵaa≡ϵv that maximizes the superconducting transition temperature Tc. The spin susceptibility weakly increases on lowering the temperature below T≃10 K, consistent with an enhanced density of states associated with passing the Fermi energy through a van Hove singularity. Although such a Lifshitz transition occurs in the γ band formed by the Ru dxy states hybridized with in-plane O pπ orbitals, the large Hund’s coupling renormalizes the uniform spin susceptibility, which, in turn, affects the hyperfine fields of all nuclei. We estimate this “Stoner” renormalization S by combining the data with first-principles calculations and conclude that this is an important part of the strain effect, with implications for superconductivity.
Citation
Luo , Y , Pustogow , A , Guzman , P , Dioguardi , A P , Thomas , S M , Ronning , F , Kikugawa , N , Sokolov , D A , Jerzembeck , F , Mackenzie , A P , Hicks , C W , Bauer , E D , Mazin , I I & Brown , S E 2019 , ' Normal state 17 O NMR studies of Sr 2 RuO 4 under uniaxial stress ' , Physical Review X , vol. 9 , no. 2 , 021044 . https://doi.org/10.1103/PhysRevX.9.021044
Publication
Physical Review X
Status
Peer reviewed
ISSN
2160-3308Type
Journal article
Rights
Copyright © 2019 The Author(s). Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Description
This work was supported in part by the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory under Project No. 20170204ER. Y. L. acknowledges partial support through the LDRD and 1000 Youth Talents Plan of China. N. K. acknowledges the support from JSPS KAKNHI (Grant No. 18K04715). I. I.M. is supported by ONR through the NRL basic research program. This work is supported in part by the National Science Foundation (Grants No. DMR-1410343 and No. DMR-1709304).Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.