arXiv:1002.4483v1 [cond-mat.mes-hall] 24 Feb 2010 Quantum Manifestations of Graphene Edge Stress and Edge Instability: A First-Principles Study Bing Huang $^{1}$, Miao Liu$^{2}$, Ninghai Su$^{2}$, Jian Wu$^{1}$, Wenhui Duan $^{1}$, Bing-lin Gu$^{1}$, and Feng Liu2 ∗ $^{1}$Department of Physics, Tsinghua University, Beijing 100084, China and $^{2}$Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (Dated: November 5, 2018) We have performed first-principles calculations of graphene edge stresses, which display two interesting quantum manifestations absent from the classical interpretation: the armchair edge stress oscillates with nanoribbon width and the zigzag edge stress is noticeably reduced by spin polarization. Such quantum stress effects in turn manifest in mechanical edge twisting and warping instability, showing features not to be captured by empirical potentials or continuum theory. Edge adsorption of H and Stone-Wales reconstruction are shown to provide alternative mechanisms in relieving the edge compression and hence to stabilize the planar edge structure. PACS numbers: 71.15.Mb,62.25.-g,61.46.-w,81.05.Tp Abstract ∗ Email: fliu@eng.utah.edu 0