BAND STRUCTURE, METALLIZATION, AND SUPERCONDUCTIVITY OF GaAs AND InAs UNDER HIGH PRESSURE

Abstract

The electronic band structure, metallization, structural phase transition, and superconductivity of cubic zinc blende type GaAs and InAs are investigated. The equilibrium lattice constant, bulk modulus, and the phase transition pressure at which the compounds undergo structural phase transition from ZnS to NaCl are predicted from the total energy calculations. The density of states at the Fermi level (N(E F )) get enhanced after metallization, which leads to the superconductivity in GaAs and InAs . The superconducting transition temperatures (T c ) of GaAs and InAs are obtained as a function of pressure for both the ZnS and NaCl structures. GaAs and InAs come under the class of pressure-induced superconductors. When pressure is increased T c increases in both the normal and high pressure-structures. The dependence of T c on electron–phonon mass enhancement factor λ shows that GaAs and InAs are electron–phonon-mediated superconductors. Also, it is found that GaAs and InAs retained in their normal structure under high pressure give appreciably high T c .