Abrupt enhancement of noncentrosymmetry and appearance of a spin-triplet superconducting state in Li2(Pd1-xPtx) 3B beyond x=0.8

S. Harada, J. J. Zhou, Y. G. Yao, Yoshihiko Inada, Guo-Qing Zheng

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

We report synthesis, 195Pt, 11B, and 7Li NMR measurements, and first-principles band calculations for noncentrosymmetric superconductors Li2(Pd1-xPtx)3B (x=0, 0.2, 0.5, 0.8, 0.84, 0.9, and 1). For 0≤x≤0.8, the spin-lattice relaxation rate 1/T 1 shows a clear coherence peak just below Tc, decreasing exponentially at low temperature, and the Knight shift 195K decreases below Tc. For x=0.9 and 1.0, in contrast, 1/T1 shows no coherence peak but a T3 variation and 195K remains unchanged across T c. These results indicate that the superconducting state changes drastically from a spin-singlet dominant to a spin-triplet dominant state at x=0.8. We find that the distortion of B(Pt,Pd)6 increases abruptly above x=0.8, which leads to an abrupt enhancement of the asymmetric spin-orbit coupling as confirmed by band calculation. Such structure distortion that enhances the extent of inversion-symmetry breaking is primarily responsible for the pairing symmetry evolution. The insight obtained here provides a guideline for searching for noncentrosymmetric superconductors with a large spin-triplet component.

Original languageEnglish
Article number220502
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume86
Issue number22
DOIs
Publication statusPublished - Dec 3 2012

Fingerprint

Superconducting materials
Spin-lattice relaxation
augmentation
Orbits
Nuclear magnetic resonance
nuclear magnetic resonance
spin-lattice relaxation
atomic energy levels
broken symmetry
inversions
orbits
Temperature
symmetry
synthesis

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

@article{1b23008d7b304d5689a8904f1b1a06d2,
title = "Abrupt enhancement of noncentrosymmetry and appearance of a spin-triplet superconducting state in Li2(Pd1-xPtx) 3B beyond x=0.8",
abstract = "We report synthesis, 195Pt, 11B, and 7Li NMR measurements, and first-principles band calculations for noncentrosymmetric superconductors Li2(Pd1-xPtx)3B (x=0, 0.2, 0.5, 0.8, 0.84, 0.9, and 1). For 0≤x≤0.8, the spin-lattice relaxation rate 1/T 1 shows a clear coherence peak just below Tc, decreasing exponentially at low temperature, and the Knight shift 195K decreases below Tc. For x=0.9 and 1.0, in contrast, 1/T1 shows no coherence peak but a T3 variation and 195K remains unchanged across T c. These results indicate that the superconducting state changes drastically from a spin-singlet dominant to a spin-triplet dominant state at x=0.8. We find that the distortion of B(Pt,Pd)6 increases abruptly above x=0.8, which leads to an abrupt enhancement of the asymmetric spin-orbit coupling as confirmed by band calculation. Such structure distortion that enhances the extent of inversion-symmetry breaking is primarily responsible for the pairing symmetry evolution. The insight obtained here provides a guideline for searching for noncentrosymmetric superconductors with a large spin-triplet component.",
author = "S. Harada and Zhou, {J. J.} and Yao, {Y. G.} and Yoshihiko Inada and Guo-Qing Zheng",
year = "2012",
month = "12",
day = "3",
doi = "10.1103/PhysRevB.86.220502",
language = "English",
volume = "86",
journal = "Physical Review B-Condensed Matter",
issn = "1098-0121",
publisher = "American Physical Society",
number = "22",

}

TY - JOUR

T1 - Abrupt enhancement of noncentrosymmetry and appearance of a spin-triplet superconducting state in Li2(Pd1-xPtx) 3B beyond x=0.8

AU - Harada, S.

AU - Zhou, J. J.

AU - Yao, Y. G.

AU - Inada, Yoshihiko

AU - Zheng, Guo-Qing

PY - 2012/12/3

Y1 - 2012/12/3

N2 - We report synthesis, 195Pt, 11B, and 7Li NMR measurements, and first-principles band calculations for noncentrosymmetric superconductors Li2(Pd1-xPtx)3B (x=0, 0.2, 0.5, 0.8, 0.84, 0.9, and 1). For 0≤x≤0.8, the spin-lattice relaxation rate 1/T 1 shows a clear coherence peak just below Tc, decreasing exponentially at low temperature, and the Knight shift 195K decreases below Tc. For x=0.9 and 1.0, in contrast, 1/T1 shows no coherence peak but a T3 variation and 195K remains unchanged across T c. These results indicate that the superconducting state changes drastically from a spin-singlet dominant to a spin-triplet dominant state at x=0.8. We find that the distortion of B(Pt,Pd)6 increases abruptly above x=0.8, which leads to an abrupt enhancement of the asymmetric spin-orbit coupling as confirmed by band calculation. Such structure distortion that enhances the extent of inversion-symmetry breaking is primarily responsible for the pairing symmetry evolution. The insight obtained here provides a guideline for searching for noncentrosymmetric superconductors with a large spin-triplet component.

AB - We report synthesis, 195Pt, 11B, and 7Li NMR measurements, and first-principles band calculations for noncentrosymmetric superconductors Li2(Pd1-xPtx)3B (x=0, 0.2, 0.5, 0.8, 0.84, 0.9, and 1). For 0≤x≤0.8, the spin-lattice relaxation rate 1/T 1 shows a clear coherence peak just below Tc, decreasing exponentially at low temperature, and the Knight shift 195K decreases below Tc. For x=0.9 and 1.0, in contrast, 1/T1 shows no coherence peak but a T3 variation and 195K remains unchanged across T c. These results indicate that the superconducting state changes drastically from a spin-singlet dominant to a spin-triplet dominant state at x=0.8. We find that the distortion of B(Pt,Pd)6 increases abruptly above x=0.8, which leads to an abrupt enhancement of the asymmetric spin-orbit coupling as confirmed by band calculation. Such structure distortion that enhances the extent of inversion-symmetry breaking is primarily responsible for the pairing symmetry evolution. The insight obtained here provides a guideline for searching for noncentrosymmetric superconductors with a large spin-triplet component.

UR - http://www.scopus.com/inward/record.url?scp=84871100019&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84871100019&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.86.220502

DO - 10.1103/PhysRevB.86.220502

M3 - Article

AN - SCOPUS:84871100019

VL - 86

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 22

M1 - 220502

ER -