Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2011 Oct 7;107(15):157201. doi: 10.1103/PhysRevLett.107.157201. Epub 2011 Oct 3.
We develop a technique to directly study spinons (emergent spin S=1/2 particles) in quantum spin models in any number of dimensions. The size of a spinon wave packet and of a bound pair (a triplon) are defined in terms of wave-function overlaps that can be evaluated by quantum Monte Carlo simulations. We show that the same information is contained in the spin-spin correlation function as well. We illustrate the method in one dimension. We confirm that spinons are well-defined particles (have exponentially localized wave packet) in a valence-bond-solid state, are marginally defined (with power-law shaped wave packet) in the standard Heisenberg critical state, and are not well defined in an ordered Néel state (achieved in one dimension using long-range interactions).
我们开发了一种技术，可以直接研究任意维度量子自旋模型中的自旋子（新兴的自旋 S=1/2 粒子）。自旋子波包和束缚对（三电子自旋态）的大小由可以通过量子蒙特卡罗模拟评估的波函数重叠来定义。我们表明，同样的信息也包含在自旋-自旋相关函数中。我们在一维中说明了这种方法。我们证实，在价键固体相中，自旋子是很好定义的粒子（具有指数局域化的波包），在标准海森堡临界态中则是勉强定义的（具有幂律形状的波包），而在有序奈尔相中则不是很好定义的（在一维中使用长程相互作用实现）。
