doi:10.1103/PhysRevLett.120.132504engMcDonald, A.D.Jones, B.J.P.Nygren, D.R.Adams, C.Álvarez, V.Azevedo, C.D.R.Benlloch-Rodríguez, J.M.Borges, F.I.G.M.Botas, A.Cárcel, S.Carrión, J.V.Cebrián, S.Conde, C.A.N.Díaz, J.Diesburg, M.Escada, J.Esteve, R.Felkai, R.Fernandes, L.M.P.Ferrario, P.Ferreira, A.L.Freitas, E.D.C.Goldschmidt, A.Gómez-Cadenas, J.J.González-Díaz, D.Gutiérrez, R.M.Guenette, R.Hafidi, K.Hauptman, J.Henriques, C.A.O.Hernandez, A.I.Hernando Morata, J.A.Herrero, V.Johnston, S.Labarga, L.Laing, A.Lebrun, P.Liubarsky, I.López-March, N.Losada, M.Martín-Albo, J.Martínez-Lema, G.Martínez, A.Monrabal, F.Monteiro, C.M.B.Mora, F.J.Moutinho, L.M.Muñoz Vidal, J.Musti, M.Nebot-Guinot, M.Novella, P.Palmeiro, B.Para, A.Pérez, J.Querol, M.Repond, J.Renner, J.Riordan, S.Ripoll, L.Rodríguez, J.Rogers, L.Santos, F.P.Dos Santos, J.M.F.Simón, A.Sofka, C.Sorel, M.Stiegler, T.Toledo, J.F.Torrent, J.Tsamalaidze, Z.Veloso, J.F.C.A.Webb, R.White, J.T.Yahlali, N.Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence ImagingART-2018-105787A new method to tag the barium daughter in the double-beta decay of Xe136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (~2 nm), and detected with a statistical significance of 12.9s over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.2018http://zaguan.unizar.es/record/7030910.1103/PhysRevLett.120.132504http://zaguan.unizar.es/record/70309oai:zaguan.unizar.es:70309info:eu-repo/grantAgreement/ES/MINECO/SEV-2014-0398info:eu-repo/grantAgreement/ES/MINECO/FIS2014-53371-C04info:eu-repo/grantAgreement/EC/FP7/339787/EU/Towards the NEXT generation of bb0nu experimets/NEXTinfo:eu-repo/grantAgreement/ES/FEDER/COMPETE/PTDC-FIS-103860-2008Physical Review Letters 120, 13 (2018), 132504 [6 pp]All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/openAccess