| The electron-hole gas is the one of the simplest periodic systems which may be studied in quantum mechanics but nevertheless it has a rich and interesting electronic structure which we are calculating with the CASINO QMC code. So far we have calculated ground state energies for the two-component plasma phase with plane wave orbitals and the excitonic insulating phase with hydrogen-like orbitals. We intend to study new types of wave function for this system with the goal of mapping out a complete phase diagram. The relevant parameters are (1) the density and (2) the mass ratio between the holes and electrons (thus we can vary the system from positronium to hydrogen, for example). Studies so far have been conducted in three dimensions. More experimentally relevant and useful studies may be performed for the two-dimensional system with a separation between the electron and hole layers, and this is our current area of research. |
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