Solitonic excitations in the Ising anisotropic chain BaCo2V2O8 under large transverse magnetic field
Solitonic excitations in the Ising anisotropic chain BaCo2V2O8 under large transverse magnetic field
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大横向磁场下伊辛各向异性链 BaCo2V2O8 的孤子激发
DOI：
10.1103/physrevresearch.3.043227
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发表时间：
2021
影响因子：
4.2
通讯作者：
Simonet Virginie
中科院分区：
文献类型：
--
作者：
Faure Quentin;Takayoshi Shintaro;Grenier Beatrice;Petit Sylvain;Raymond Stephane;Boehm Martin;Lejay Pascal;Giamarchi Thierry;Simonet Virginie
我们研究了横向磁场下准一维伊辛-海森堡反铁磁体的动力学。结合非弹性中子散射实验以及场论和数值模拟的理论分析，我们主要阐明了出现在量子相变点上方的高场相中的自旋激发谱的结构。我们发现它的特点是叠加在连续体上的集体孤子激发。由于化合物的非对角张量引起的有效交错场，这些孤子紧密地成对束缚，并且在拓扑上不同于弱场区域中的分级自旋子。使用无限时间演化块抽取方法数值计算的动态磁化率与测量的光谱非常吻合，这使我们能够识别基本激发的色散分支。最低能量色散具有不可通约的性质，并且由于施加的横向场而在无理波数处具有局部最小值。
We study the dynamics of the quasi-one-dimensional Ising-Heisenberg antiferromagnetunder a transverse magnetic field. Combining inelastic neutron scattering experiments and theoretical analyses by field theories and numerical simulations, we mainly elucidate the structure of the spin excitation spectrum in the high-field phase, appearing above the quantum phase transition point. We find that it is characterized by collective solitonic excitations superimposed on a continuum. These solitons are strongly bound in pairs due to the effective staggered field induced by the nondiagonaltensor of the compound and are topologically different from the fractionalized spinons in the weak-field region. The dynamical susceptibility numerically calculated with the infinite time-evolving block decimation method shows an excellent agreement with the measured spectra, which enables us to identify the dispersion branches with elementary excitations. The lowest-energy dispersion has an incommensurate nature and has a local minimum at an irrational wave number due to the applied transverse field.