Quantum Lifshitz Field Theory of a Frustrated Ferromagnet
Quantum Lifshitz Field Theory of a Frustrated Ferromagnet
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DOI：
10.1103/physrevlett.116.177201
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发表时间：
2016-04-27
影响因子：
8.6
通讯作者：
Starykh, Oleg A.
中科院分区：
文献类型：
--
作者：
Balents, Leon;Starykh, Oleg A.
我们提出了一种适用于一维受抑铁磁体的通用非线性 sigma 模型场理论，该理论适用于“量子 Lifshitz 点”附近，在该点铁磁态会产生自旋波不稳定性。我们研究了由交换和远离 Lifshitz 点的磁场扰动产生的相图，并揭示了具有两种不同属性的不同状态的丰富结构，具体取决于理论的边际无量纲参数的值。在与低自旋一维系统相关的区域中，我们发现了矢量手性相的变磁转变线。这条线终止于一个临界终点，超过该终点时，存在至少一个多极或“自旋向列”相。我们证明场论在 Lifshitz 点附近是渐近完全可溶的。
We propose a universal nonlinear sigma model field theory for one-dimensional frustrated ferromagnets, which applies in the vicinity of a "quantum Lifshitz point," at which the ferromagnetic state develops a spin wave instability. We investigate the phase diagram resulting from perturbations of the exchange and of magnetic field away from the Lifshitz point, and uncover a rich structure with two distinct regimes of different properties, depending upon the value of a marginal, dimensionless, parameter of the theory. In the regime relevant for one-dimensional systems with low spin, we find a metamagnetic transition line to a vector chiral phase. This line terminates in a critical end point, beyond which there is at least one multipolar or "spin nematic" phase. We show that the field theory is asymptotically exactly soluble near the Lifshitz point.