000095504 001__ 95504 000095504 005__ 20210902121730.0 000095504 0247_ $$2doi$$a10.1007/JHEP08(2020)144 000095504 0248_ $$2sideral$$a119576 000095504 037__ $$aART-2020-119576 000095504 041__ $$aeng 000095504 100__ $$0(orcid)0000-0003-3669-6241$$aAsorey, M.$$uUniversidad de Zaragoza 000095504 245__ $$aThe critical transition of Coulomb impurities in gapped graphene 000095504 260__ $$c2020 000095504 5060_ $$aAccess copy available to the general public$$fUnrestricted 000095504 5203_ $$aThe effect of supercritical charge impurities in graphene is very similar to the supercritical atomic collapses in QED for Z > 137, but with a much lower critical charge. In this sense graphene can be considered as a natural testing ground for the analysis of quantum field theory vacuum instabilities. We analyze the quantum transition from subcritical to supercritical charge regimes in gapped graphene in a common framework that preserves unitarity for any value of charge impurities. In the supercritical regime it is possible to introduce boundary conditions which control the singular behavior at the impurity. We show that for subcritical charges there are also non-trivial boundary conditions which are similar to those that appear in QED for nuclei in the intermediate regime 118 < Z < 137. We analyze the behavior of the energy levels associated to the different boundary conditions. In particular, we point out the existence of new bound states in the subcritical regime which include a negative energy bound state in the attractive Coulomb regime. A remarkable property is the continuity of the energy spectral flow under variation of the impurity charge even when jumping across the critical charge transition. We also remark that the energy levels of hydrogenoid bound states at critical values of charge impurities act as focal points of the spectral flow. 000095504 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/ 000095504 590__ $$a5.81$$b2020 000095504 591__ $$aPHYSICS, PARTICLES & FIELDS$$b5 / 29 = 0.172$$c2020$$dQ1$$eT1 000095504 592__ $$a0.998$$b2020 000095504 593__ $$aNuclear and High Energy Physics$$c2020$$dQ2 000095504 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000095504 700__ $$0(orcid)0000-0003-2072-1182$$aSantagata, A. 000095504 7102_ $$12004$$2405$$aUniversidad de Zaragoza$$bDpto. Física Teórica$$cÁrea Física Teórica 000095504 773__ $$g2020, 8 (2020), 144 1-26$$pJ. high energy phys.$$tJournal of High Energy Physics$$x1126-6708 000095504 8564_ $$s806279$$uhttps://zaguan.unizar.es/record/95504/files/texto_completo.pdf$$yVersión publicada 000095504 8564_ $$s23783$$uhttps://zaguan.unizar.es/record/95504/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000095504 909CO $$ooai:zaguan.unizar.es:95504$$particulos$$pdriver 000095504 951__ $$a2021-09-02-09:35:26 000095504 980__ $$aARTICLE