Phases of 4He and H2 adsorbed on a single carbon nanotube Gordillo Bargueño, María Carmen Rodríguez-García, R. Boronat, Jordi We acknowledge financial support from Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 (Spain) under Grants No. PID2020-113565GB-C22 and No. PID2020-113565GB-C21 and from Junta de Andalucía group PAIDI-205. M.C.G. acknowledges funding from European regional development fund (FEDER) and Junta de Andalucía Economy, Knowledge, Bussiness and University Consejería under ther especific goal 1.2.3 of the FEDER program Andalucía 2014-2020 “Promotion and generation of frontier knowledge and knowledge aimed at the challenges of society, development of emerging technologies.” under Grant No. UPO-1380159, FEDER-financed percentage 80%, and from AGAUR-Generalitat de Catalunya Grant No. 2021-SGR-01411. We also acknowledge the use of the C3UPO computer facilities at the Universidad Pablo de Olavide. Using a diffusion Monte Carlo technique, we calculated the phase diagrams of 4He and H2 adsorbed on a single (5,5) carbon nanotube, one of the narrowest that can be obtained experimentally. For a single monolayer, when the adsorbate density increases, both species undergo a series of first-order solid-solid phase transitions between incommensurate arrangements. Remarkably, the 4He lowest-density solid phase shows supersolid behavior, in contrast to the normal solid that we found for H2. The nature of the second layer is also different for both adsorbates. Contrary to what happens on graphite, the second layer of 4He on the tube is a liquid, at least up to the density corresponding to a third-layer promotion on a flat substrate. However, the second layer of H2 is a solid that, at its lowest stable density, has a small, but observable, superfluid fraction. 2023-06-29T10:28:58Z 2023-06-29T10:28:58Z 2023-05-22 journal article M. C. Gordillo, R. Rodríguez-García, and J. Boronat. Phases of 4He and H2 adsorbed on a single carbon nanotube. Phys. Rev. B 107, 174518. [DOI: 10.1103/PhysRevB.107.174518] https://hdl.handle.net/10481/82971 10.1103/PhysRevB.107.174518 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional American Physical Society