发表机构
The Rudolf Peierls Centre for Theoretical Physics, Oxford University（牛津大学鲁道夫·皮尔斯理论物理中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过数值研究各向异性自旋-1链，验证了Nahum理论：U(1)对称破缺导致长程有序，磁化指数约0.29，动力学临界指数约2。
AI 中文摘要
在最近的一篇论文中，Nahum基于重整化群分析提出，与标准观点相反，具有短程相互作用的一维自旋链的基态可以自发破缺U(1)“易平面”自旋旋转对称性。$(S^x,S^y)$的真正长程有序出现在两个准长程有序相之间的相变处。本文我们给出了一个各向异性自旋-1链模型的详细数值结果。我们发现磁化指数$\beta\approx0.29$，与$\epsilon$展开预测$\beta\approx0.28$一致；从两侧接近相变时Luttinger参数发散，其指数与Nahum的相变相关；有限尺寸谱与动力学临界指数$z\approx2$一致。我们的结果支持Nahum场论所预测的临界行为。
英文摘要
In a recent paper Nahum argued on the basis of a renormalization-group analysis that, contrary to standard lore, ground states of 1D spin chains with short-range interactions can spontaneously break U(1) ``easy-plane'' spin rotation symmetry. True long-range order of $(S^x,S^y)$ arises at the phase transition between two quasi-long-range-ordered phases. Here we present detailed numerical results for an anisotropic spin-1 chain model. We find a magnetization exponent $β\approx0.29$, consistent with the $ε$-expansion prediction $β\approx0.28$, a divergence of the Luttinger parameter on approaching the transition from both sides with an exponent that we relate to Nahum's transition, and finite-size spectra consistent with a dynamical critical exponent $z\approx2$. Our results support the critical behavior predicted by Nahum's field theory.
Comments21 pages, 16 figures
