Structure of metastable 2D liquid helium

Abstract

We present diffusion Monte Carlo (DMC) results on a new metastable, superfluid phase above the crystal ground state in two-dimensional 4He at densities > 0.065 1/A^2. The state is anisotropic with hexatic orbital order. This implies that the liquid--solid phase transition has two stages: A second order phase transition from the isotropic superfluid to the hexatic superfluid, followed by a first order transition that localizes atoms into the triangular crystal order. This metastable hexatic phase has finite condensate fraction and it provides a natural explanation for the superflow in the supersolid grain boundaries.

References in corpus (4)

• Unbiased estimators in Quantum Monte Carlo methods: application to liquid ${}^4$He
• Diffusion Monte Carlo study of two-dimensional liquid ${}^4$He
• Quantum Monte Carlo simulation of overpressurized liquid 4He
• Layer- and bulk roton excitations of 4He in porous media

Cited by in corpus (6)

• Possible quantum liquid crystal phases of helium monolayers
• Metastable Patterns in one- and two-component dipolar Bose-Einstein Condensates
• Superfluid and supersolid phases of 4He on the second layer of graphite
• Dynamic many-body theory: Dynamic structure factor of two-dimensional liquid ${}^4$He
• Fluid and registered phases in the second layer of 3He on graphite
• Phase diagram and crystal melting of helium-4 in two dimensions