engleski

Quantum Monte Carlo study of overpressurized liquid 4He at zero temperature

We present a diffusion Monte Carlo simulation of metastable superfluid 4He at zero temperature and pressures beyond freezing (~ 25 bar) up to 275 bar. The equation of state of liquid 4He is extended to the overpressurized regime, where the pressure dependence of the static structure factor and the condensate fraction is obtained. Along this large pressure range, excited-state energy corresponding to the roton has been determined using the release-node technique. Our results show that both the roton energies and the condensate fraction decrease with increasing pressure but do not become zero. We compare our calculations to recent experimental data in overpressurized regime.

he-4; excitations; superfluid helium; roton; Monte Carlo

Navedini rad je objavljen i u časopisu: International Journal of Modern Physics B, Vol. 20, No. 30-31, pp. 5154-5163, Special Issue (2006)