First produced in a lab back in 2004, graphene is essentially a single layer of pure carbon atoms bonded together in a honeycomb lattice so thin it's actually considered two-dimensional.
Physicists often work with finite "lattice" models—generalizations of two-dimensional checkerboards—as approximations to continuous reality.
物理学家的研究经常要使用有限格模型——二维棋盘的扩展——作为对连续实在的逼近。
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In this article, the critical exponents of the polymer model SAT in twodimensional square lattice have been studied with the real space renormalization theory.