扩展Lieb晶格上自旋-1/2海森堡反铁磁体中的场驱动量子相变
Field-driven quantum phase transitions in a spin-1/2 Heisenberg antiferromagnet on an extended Lieb lattice
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中文总结 AI 辅助
本研究通过密度矩阵重正化群和量子蒙特卡洛方法，揭示了扩展Lieb晶格自旋-1/2海森堡反铁磁体在磁场下的量子相变，包括1/5和3/5磁化平台及无能隙自旋倾斜相，并确认了有限温度下的相应特征。
中文摘要 AI 辅助
研究了在外部磁场存在下，扩展Lieb晶格上自旋-1/2海森堡反铁磁体的磁性行为。利用密度矩阵重正化群计算，我们确定了零温磁化曲线，并在磁场与相互作用比平面上构建了基态相图。根据相互作用比的不同，零温磁化曲线表现出场驱动的量子相变，介于有能隙相之间，表现为饱和磁化强度的1/5和3/5处的中间平台，以及无能隙的自旋倾斜相，在该相中磁化强度随外加磁场连续变化。量子蒙特卡洛模拟揭示了场致量子相变和中间磁化平台的清晰有限温度特征，而它们没有提供连续或不连续热相变的证据。
英文摘要
The magnetic behavior of the spin-1/2 Heisenberg antiferromagnet on the extended Lieb lattice is examined in the presence of an external magnetic field. Using density matrix renormalization group calculations, we determine the zero-temperature magnetization curves and construct the ground-state phase diagram in the magnetic field vs. the interaction ratio plane. Depending on the interaction ratio, the zero-temperature magnetization curves exhibit field-driven quantum phase transitions between the gapped phases manifested as the intermediate plateaus at $1/5$ and $3/5$ of the saturation magnetization and a gapless spin-canted phase, in which the magnetization varies continuously with the applied magnetic field. Quantum Monte Carlo simulations reveal clear finite-temperatures signatures of the field-induced quantum phase transitions and the intermediate magnetization plateaus, while they provide no evidence for either continuous or discontinuous thermal phase transitions.
发表机构
- Institute of Physics, Faculty of Science, P. J. Šafárik University（P. J. 沙法里克大学理学院物理研究所）
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