Xu Cenke, Sachdev Subir
Department of Physics, Harvard University, Cambridge Massachusetts 02138, USA.
Phys Rev Lett. 2008 Apr 4;100(13):137201. doi: 10.1103/PhysRevLett.100.137201. Epub 2008 Apr 2.
We propose a critical spin liquid ground state for S=1/2 antiferromagnets on the square lattice. In a renormalization group analysis of the "staggered flux" algebraic spin liquid, we examine perturbations, present in the antiferromagnet, which break its global SU(4) symmetry to SO(5). At physical parameter values, we find an instability towards a fixed point with SO(5) symmetry. We discuss the possibility that this fixed point describes a transition between the Néel and valence bond solid states, and the relationship to the SO(5) nonlinear sigma model of Tanaka and Hu.
我们提出了一种正方形晶格上S = 1/2反铁磁体的临界自旋液体基态。在对“交错磁通”代数自旋液体的重整化群分析中，我们研究了反铁磁体中存在的微扰，这些微扰将其全局SU(4)对称性破缺为SO(5)。在物理参数值下，我们发现朝向具有SO(5)对称性的不动点存在不稳定性。我们讨论了这个不动点描述奈尔态和价键固态之间转变的可能性，以及与田中（Tanaka）和胡（Hu）的SO(5)非线性西格玛模型的关系。
