Symmetry-induced gap opening in graphene superlattices Export

@article{citeulike:5944135, abstract = {We study nxn honeycomb superlattices of defects in graphene. The considered defects are missing p\_z orbitals and can be realized by either introducing C atom vacancies or chemically binding simple atomic species at the given sites. Using symmetry arguments we show how it is possible to open a gap when n=3m+1,3m+2 (m integer), and estimate its value to have an approximate square-root dependence on the defect concentration x=1/n^2. Tight-binding calculations confirm these findings and show that the induced-gaps can be quite large, e.g. \~{}100 meV for x\~{}10^{-3}. Gradient-corrected density functional theory calculations on a number of superlattices made by H atoms adsorbed on graphene are in good agreement with tight-binding results, thereby suggesting that the proposed structures may be used in practice to open a gap in graphene.}, archivePrefix = {arXiv}, author = {Martinazzo, Rocco and Casolo, Simone and Tantardini, Gian F.}, citeulike-article-id = {5944135}, citeulike-linkout-0 = {http://arxiv.org/abs/0910.2407}, citeulike-linkout-1 = {http://arxiv.org/pdf/0910.2407}, day = {13}, eprint = {0910.2407}, keywords = {antidot, defect, graphene, tb}, month = {Oct}, posted-at = {2009-10-15 15:11:27}, priority = {2}, title = {Symmetry-induced gap opening in graphene superlattices}, url = {http://arxiv.org/abs/0910.2407}, year = {2009} }

TY - JOUR ID - citeulike:5944135 L3 - citeulike-article-id:5944135 N2 - We study nxn honeycomb superlattices of defects in graphene. The considered defects are missing p_z orbitals and can be realized by either introducing C atom vacancies or chemically binding simple atomic species at the given sites. Using symmetry arguments we show how it is possible to open a gap when n=3m+1,3m+2 (m integer), and estimate its value to have an approximate square-root dependence on the defect concentration x=1/n^2. Tight-binding calculations confirm these findings and show that the induced-gaps can be quite large, e.g. ~100 meV for x~10^{-3}. Gradient-corrected density functional theory calculations on a number of superlattices made by H atoms adsorbed on graphene are in good agreement with tight-binding results, thereby suggesting that the proposed structures may be used in practice to open a gap in graphene. TI - Symmetry-induced gap opening in graphene superlattices KW - antidot KW - defect KW - graphene KW - tb AU - Martinazzo, Rocco AU - Casolo, Simone AU - Tantardini, Gian PY - 2009/Oct/13/ UR - http://arxiv.org/abs/0910.2407 ER -