Strain-induced superfluid transition for atoms on graphene

TL;DR

This paper demonstrates that applying strain to graphene can induce a superfluid transition in adsorbed bosonic atoms, revealing new quantum phases and states of matter in a highly tunable two-dimensional system.

Contribution

It shows that strain engineering of graphene enables the emergence of superfluid and other exotic quantum phases of adsorbed atoms, a novel approach in quantum many-body physics.

Findings

Strain induces superfluid phases in adsorbed atoms on graphene.

Multiple atomic solid and superfluid states are accessible via lattice expansion.

Superfluid phases occur at feasible strain levels, with potential for supersolids.

Abstract

Bosonic atoms deposited on atomically thin substrates represent a playground for exotic quantum many-body physics due to the highly-tunable, atomic-scale nature of the interaction potentials. The ability to engineer strong interparticle interactions can lead to the emergence of complex collective atomic states of matter, not possible in the context of dilute atomic gases confined in optical lattices. While it is known that the first layer of adsorbed helium on graphene is permanently locked into a solid phase, we show by a combination of quantum Monte Carlo and mean-field techniques, that simple isotropic graphene lattice expansion effectively unlocks a large variety of two-dimensional ordered commensurate, incommensurate, cluster atomic solid, and superfluid states for adsorbed atoms. It is especially significant that an atomically thin superfluid phase of matter emerges under experimentally feasible strain values, with potentially supersolid phases in close proximity on the phase diagram.