Path Integral Calculation of 4He in One-Dimensional Channel Model

Abstract

We consider 4He particles confined in a nanoscale quasi-one-dimensional channel in the liquid density range and numerically calculate the total energy per particle and the superfluid fraction by an imaginary time path integral Monte Carlo method. TBEC at which the total energy drops owing to particle exchange, shifts to a lower value with decreasing channel diameter, and disappears below a diameter of 0.48 nm. It was found that TBEC is close to the superfluid onset temperature observed in the torsional oscillator experiment. In addition, the superfluid fraction along the channel grows slowly below TBEC. Its magnitude decreases with increasing channel length, and the superfluid coherence in terms of thermodynamics disappears in infinitely long channels.