A Luttinger liquid core inside helium-4 filled nanopores

We study the effects of confining helium-4 at low temperatures inside long narrow pores with nanometer radii using worm algorithm path integral quantum Monte Carlo. The results show that even in the phase with a finite superfluid response, the interaction between helium atoms and the surface of the pore induces radial density oscillations which decay as the center of the pore is approached. For some special radii, an ``inner tube'' of helium atoms exists, and a careful scaling analysis confirms that it behaves like a one dimensional Luttinger liquid at low energies.