Bose-Einstein Quantum Statistics and the Ground State of Solid 4He

Abstract

The ground state of solid ${}^4$He is studied using the diffusion Monte Carlo method and a new trial wave function able to describe the supersolid. The new wave function is symmetric under the exchange of particles and reproduces the experimental equation of state. Results for the one-body density matrix show the existence of off-diagonal long-range order with a very small condensate fraction $\sim 10^{-4}$. The superfluid density of the commensurate system is below our resolution threshold, ${\rho }_s/\rho <10^{-5}$. With a 1% concentration of vacancies the superfluid density is manifestly larger, ${\rho }_s/\rho =3.2(1)\cdot 10^{-3}$.

5 pages, 4 figures

References in corpus (3)

• Luttinger Liquid in the Core of Screw Dislocation in Helium-4
• Ring exchanges and the supersolid phase of 4He
• Nonclassical rotational inertia for a supersolid under rotation