Distinct reduction of Knight shift in superconducting state of Sr_{2}RuO_{4} under uniaxial strain

Shortly after the discovery of superconductivity in Sr_{2}RuO_{4}, spin-triplet pairing was proposed and further corroborated by a constant Knight shift (K) across the transition temperature (T_{c}). However, a recent experiment observed a drop in K at T_{c} which becomes larger under uniaxial strai...

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Bibliographic Details
Main Authors: Austin W. Lindquist, Hae-Young Kee
Format: Article
Language:English
Published: American Physical Society 2020-08-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.2.032055
Description
Summary:Shortly after the discovery of superconductivity in Sr_{2}RuO_{4}, spin-triplet pairing was proposed and further corroborated by a constant Knight shift (K) across the transition temperature (T_{c}). However, a recent experiment observed a drop in K at T_{c} which becomes larger under uniaxial strain, ruling out several spin-triplet scenarios. Here we show that even parity interorbital spin-triplet pairing can feature a d vector that rotates when uniaxial strain is applied, leading to a larger drop in the spin polarization perpendicular to the strain direction, distinct from spin-singlet pairing. We propose that anisotropic spin polarization under strain will ultimately differentiate triplet versus singlet pairing.
ISSN:2643-1564