摘要
利用线性自旋波理论和量子蒙特卡罗方法研究了弯曲应变下六角晶格量子反铁磁体的赝朗道能级.通过线性自旋波理论,发现磁赝朗道能级出现在磁子能谱的高能端,其能级间距与能级指数的平方根成正比.线性自旋波理论和量子蒙特卡罗方法都显示,尺寸相同时随着应变强度的逐渐增加,局域磁化强度逐渐减弱,应变强度相同的条件下反铁磁序在y方向上连续减弱,因为上边界处的海森伯链解耦为孤立的垂直链,导致上边界附近的磁序被破坏.量子蒙特卡罗方法提供了更精确的反铁磁序演化:在特定应变强度下上边界处垂直关联不变,水平关联增加,从而影响磁化强度,使局域磁化在上边界处呈上翘趋势.研究结果有助于理解弯曲应变对自旋激发的影响,并可能在二维量子磁性材料实验中得以实现.
The pseudo-Landau energy levels of a hexagonal lattice quantum antiferromagnet under bending strain are studied by linear spin-wave theory(LSWT)and quantum Monte Carlo method(QMC).Using the linear spin wave theory,the magnetic pseudo-Landau energy level can be found to appear at the high-energy end of the magnon spectrum,and the energy level spacing is proportional to the square root of the energy level index.The linear spin wave theory and the quantum Monte Carlo method both indicate that at the same size,the local magnetization gradually weakens with the gradual increase of the strain strength.Additionally,the antiferromagnetic order continuously weakens in the y-direction under the same strain strength.This occurs because the Heisenberg chain on the upper boundary becomes decoupled into an isolated vertical chain,leading to the destruction of the magnetic order near the upper boundary.The quantum Monte Carlo method provides a more accurate antiferromagnetic sequence evolution,that is,the vertical correlation at the upper boundary is unchanged and the horizontal correlation increases under a specific strain intensity.This affects the magnetization intensity,so that the local magnetization shows an upward trend at the upper boundary.The results contribute to the understanding of the effect of bending strain on spin excitations,and this effect may be observed in two-dimensional quantum magnetic material experiments.
作者
解晓洁
孙俊松
秦吉红
郭怀明
Xie Xiao-Jie;Sun Jun-Song;Qin Ji-Hong;Guo Huai-Ming(Department of Physics,University of Science and Technology Beijing,Beijing 100083,China;Institute of Theoretical Physics,University of Science and Technology Beijing,Beijing 100083,China;Department of Physics,Beihang University,Beijing 100191,China)
出处
《物理学报》
SCIE
EI
CSCD
北大核心
2024年第2期49-58,共10页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11774019,12074022)
中央高校基本科研业务费(批准号:FRF-BR-16-014A)资助的课题。
作者简介
通信作者:秦吉红.E-mail:jhqin@sas.ustb.edu.cn。
