Clericò, VitoDelgado Notario, J. A.Saiz Bretín, MartaMalyshev, AndreyMeziani, Y. M.Hidalgo Alcalde, PedroMéndez Martín, BianchiAmado, M.Domínguez-Adame Acosta, FranciscoDíaz Fernández, Enrique2023-06-172023-06-172019-09-192045-232210.1038/s41598-019-50098-zhttps://hdl.handle.net/20.500.14352/13731© The Author(s) 2019 This research has been supported by the Agencia Estatal de Investigacion of Spain (Grants MAT2015-65274-R, MAT2016-75955 and TEC2015-65477-R), and the Junta de Castilla y Leon (Grant SA256P18), including FEDER funds from the European Commission. V. C. acknowledges N. Tombros and P. J. Zomer for introducing him in the transfer technique of two-dimensional materials. We are also thankful to D. Lopez and M. Velazquez for their kind help with Raman measurements and G. Kimbell for a critical reading of the manuscript.We report on a novel implementation of the cryo-etching method, which enabled us to fabricate low-roughness hBN-encapsulated graphene nanoconstrictions with unprecedented control of the structure edges; the typical edge roughness is on the order of a few nanometers. We characterized the system by atomic force microscopy and used the measured parameters of the edge geometry in numerical simulations of the system conductance, which agree quantitatively with our low temperature transport measurements. The quality of our devices is confirmed by the observation of well defined quantized 2e^2/h conductance steps at zero magnetic field. To the best of our knowledge, such an observation reports the clearest conductance quantization in physically etched graphene nanoconstrictions. The fabrication of such high quality systems and the scalability of the cryo-etching method opens a novel promising possibility of producing more complex truly-ballistic devices based on graphene.engAtribución 3.0 Españajournal articlehttp://dx.doi.org/10.1038/s41598-019-50098-zhttps://www.nature.com/open access538.9Multidisciplinary SciencesGrapheneFísica de materialesFísica del estado sólido2211 Física del Estado Sólido