在受挫和各向异性自旋链 cuprate LiCuSbO 中磁场诱导非常规向列液体的特征。

Signatures of a magnetic field-induced unconventional nematic liquid in the frustrated and anisotropic spin-chain cuprate LiCuSbO.

机构信息

Leibniz Institute for Solid State and Materials Research IFW-Dresden, D-01171, Dresden, Germany.

Institute for Theoretical Physics, Technical University Dresden, D-01069, Dresden, Germany.

出版信息

Sci Rep. 2017 Jul 27;7(1):6720. doi: 10.1038/s41598-017-06525-0.

DOI:10.1038/s41598-017-06525-0

PMID:28751668

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5532373/

Abstract

Modern theories of quantum magnetism predict exotic multipolar states in weakly interacting strongly frustrated spin-1/2 Heisenberg chains with ferromagnetic nearest neighbor (NN) inchain exchange in high magnetic fields. Experimentally these states remained elusive so far. Here we report strong indications of a magnetic field-induced nematic liquid arising above a field of ~13 T in the edge-sharing chain cuprate LiSbCuO ≡ LiCuSbO. This interpretation is based on the observation of a field induced spin-gap in the measurements of the Li NMR spin relaxation rate T as well as a contrasting field-dependent power-law behavior of T vs. T and is further supported by static magnetization and ESR data. An underlying theoretical microscopic approach favoring a nematic scenario is based essentially on the NN XYZ exchange anisotropy within a model for frustrated spin-1/2 chains and is investigated by the DMRG technique. The employed exchange parameters are justified qualitatively by electronic structure calculations for LiCuSbO.

摘要

现代量子磁学理论预测，在磁场中具有铁磁近邻（NN）的弱相互作用强受挫自旋-1/2 Heisenberg 链中，存在奇特的多极态。到目前为止，实验上这些状态仍然难以捉摸。在这里，我们报告了在边缘共享链 cuprate LiSbCuO ≡ LiCuSbO 中，磁场诱导的向列液体在约 13 T 的磁场以上出现的强烈迹象。这一解释是基于对 Li NMR 自旋弛豫率 T ¹ 的测量中观察到的磁场诱导能隙以及 T ¹ 与 T 和 T 的对比场依赖性幂律行为的观察得出的，并得到了静态磁化强度和 ESR 数据的进一步支持。支持向列相的基本理论微观方法基于受挫自旋-1/2 链模型中的 NN XYZ 交换各向异性，并通过 DMRG 技术进行了研究。所采用的交换参数通过 LiCuSbO 的电子结构计算得到了定性的证明。