Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2013 May 24;110(21):217213. doi: 10.1103/PhysRevLett.110.217213.
We use Monte Carlo methods to study spinons in two-dimensional quantum spin systems, characterizing their intrinsic size λ and confinement length Λ. We confirm that spinons are deconfined, Λ→∞ and λ finite, in a resonating valence-bond spin-liquid state. In a valence-bond solid, we find finite λ and Λ, with λ of a single spinon significantly larger than the bound state-the spinon is soft and shrinks as the bound state is formed. Both λ and Λ diverge upon approaching the critical point separating valence-bond solid and Néel ground states. We conclude that the spinon deconfinement is marginal in the lowest-energy state in the spin-1 sector, due to weak attractive spinon interactions. Deconfinement in the vicinity of the critical point should occur at higher energies.
我们使用蒙特卡罗方法研究二维量子自旋系统中的自旋子，其特征是内在大小 λ 和限制长度 Λ。我们证实，在共振价带自旋液体状态下，自旋子是无限制的，Λ→∞且 λ 有限。在价带固体中，我们发现 λ 和 Λ 是有限的，单个自旋子的 λ 明显大于束缚态——自旋子是软的，并随着束缚态的形成而收缩。当接近分离价带固体和奈尔基态的临界点时， λ 和 Λ 都会发散。我们的结论是，由于弱吸引自旋子相互作用，在自旋为 1 的最低能量态中，自旋子的去禁闭是边缘的。在临界点附近的去禁闭应该在更高的能量下发生。
