H2 superglass on an amorphous carbon substrate

Abstract

The phase diagram of a para-H2 monolayer absorbed on a experimentally syntetized amorphous carbon sheet was calculated using a diffusion Monte Carlo technique. We found that the ground state of that system changed drastically from a perfectly flat substrate to a situation in which the carbon atoms were allowed a certain degree of disorder in the $z$ direction. In the first case, at zero pressure we have a glass of density 0.056 $\pm$ 0.003 Å${}^{-2}$ in equilibrium with an incommensurate solid of 0.068 $\pm$ 0.002 Å${}^{-2}$. At the equilibrium density, the glass was found to have a tiny, but non-negligible superfluid faction of less than 1 \% (0.44 $\pm$ 0.05 \%). In the $z$-disordered substrate, we observe a significant enhancement of the superfluid fraction in the glass phase as well as a smaller but not zero value in the incommensurate crystal.

References in corpus (16)

• Electric Field Effect in Atomically Thin Carbon Films
• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
• Two Dimensional Atomic Crystals
• From Point Defects in Graphene to Two-Dimensional Amorphous Carbon
• Synthesis and properties of free-standing monolayer amorphous carbon
• 4He on a single graphene sheet
• Quantum simulations of the superfluid-insulator transition for two-dimensional, disordered, hard-core bosons
• Ab initio simulation of amorphous graphite
• Pentagonal puckering in a sheet of amorphous graphene
• Spatially Modulated Superfluid State in Two-Dimensional ${}^4$He Films
• Superfluidity of metastable bulk glass para-hydrogen at low temperature
• Phase diagram of H2 adsorbed on graphene
• Superfluid and supersolid phases of 4He on the second layer of graphite
• Second layer of H2 and D2 adsorbed on graphene
• Supersolidity in the second layer of $para$-H${}_2$ adsorbed on graphite

Cited by in corpus (1)

• Phases of ${}^4$He and H${}_2$ adsorbed on a single carbon nanotube