95504 20210902121730.0 doi 10.1007/JHEP08(2020)144 sideral 119576 ART-2020-119576 eng Asorey, M. Universidad de Zaragoza (orcid)0000-0003-3669-6241 The critical transition of Coulomb impurities in gapped graphene 2020 Access copy available to the general public Unrestricted The 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. info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 5.81 2020 PHYSICS, PARTICLES & FIELDS 5 / 29 = 0.172 2020 Q1 T1 0.998 2020 Nuclear and High Energy Physics 2020 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Santagata, A. (orcid)0000-0003-2072-1182 2004 405 Universidad de Zaragoza Dpto. Física Teórica Área Física Teórica 2020, 8 (2020), 144 1-26 J. high energy phys. Journal of High Energy Physics 1126-6708 806279 http://zaguan.unizar.es/record/95504/files/texto_completo.pdf Versión publicada 23783 http://zaguan.unizar.es/record/95504/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:95504 articulos driver 2021-09-02-09:35:26 ARTICLE