Abstract
We examine a mixture of electrons and holes in semiconductors. It is well known that in such a system the effective Coulomb interaction is perfectly screened at long distances, which leads to Mott's metal-insulator phase transition. We show that the screening is not monotonic and at intermediate ranges there are regions of over-screening, which at low densities become strong enough to destroy the homogeneous mixture by clustering charges. We suggest that this phenomenon is responsible for the broad density distribution of the electron-hole liquid and the condensed plasma phase in silicon suggested by Smith and Wolfe (1995 Phys. Rev. B 51 7521). When the hole mass is set equal to the proton mass we can study properties of the metallic hydrogen and show that at high pressures there is a phase transition into a crystal phase of protons.
Original language | British English |
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Pages (from-to) | 9223-9236 |
Number of pages | 14 |
Journal | Journal of Physics A: Mathematical and General |
Volume | 36 |
Issue number | 35 SPEC. ISS. |
DOIs | |
State | Published - 5 Sep 2003 |