The ground state energy of two-dimensional electron-hole metallic liquid is calculated with use of the generalized random phase approximation of Hubbard. The following two cases are treated to investigate effects of dimensionality and many-valley structure: (i) the system with a single extremum in conduction and valence bands and (ii) the system with the many-valley structure in the conduction band. It is shown that the ground state energy of the two-dimensional system is four times larger than that of corresponding three-dimensional system in the case (i) while it becomes more than four times larger in the case (ii) where the effective mass of electrons is lighter than that of holes. A possibility of producing the electron-hole pancake in highly excited layer-type semiconductors is pointed out. The dispersion relations of two-dimensional plasmons and acoustic modes are also derived.
ASJC Scopus subject areas
- Physics and Astronomy(all)