Propagating microscopic temperature fluctuations in a dense helium fluid at 13.3 K.

Abstract

A neutron-scattering experiment on dense semiclassical helium at 13.3 K and 203 bars reveals that the dynamic structure factor S(k,\ensuremath{\omega}) has a clearly visible side peak at the frequency ${\mathrm{\ensuremath{\omega}}}_{\mathit{T}}$(k) for wave numbers 3\ensuremath{\le}k\ensuremath{\le}11 ${\mathrm{nm}}^{\mathrm{\ensuremath{-}}1}$. ${\mathrm{\ensuremath{\omega}}}_{\mathit{T}}$ is the oscillation frequency of propagating temperature fluctuations, an effect not seen in dense classical fluids.