QUANTUM FLUID MIXTURES IN DIFFERENT PHASES

Abstract

Variational theory of quantum fluid mixtures is presented with the emphasis on the stability and phase transitions. We give results on two systems where new interesting phases are predicted. Dilute mixtures of 3 He impurities in the liquid 4 He in two dimensions form loosely bound pairs, dimers. The binding energy of the dimer ranges from milli- to micro-Kelvins with increasing 4 He density. The dimerised mixture of 3 He atoms is stable up to maximum solubility of ≈3%. Electrons and holes in semiconductors form a homogeneous mixture, electron-hole liquid. We predict that at low densities this system becomes unstable against clustering of charges and a liquid phase with a mixture of bound charged clusters could be formed.