MONTE-CARLO SIMULATION FOR THE TRANSPORT-PROPERTIES OF QUASI-PARTICLES IN SUPERCONDUCTORS

The transport properties of low energy quasiparticles across the base layer in superconducting base transistors has been described using the Boltzmann equation which is based on the BCS theory. In order to investigate these transport properties, the Boltzmann equation was solved by means of the Monte-Carlo method which includes the acoustic phonon scattering mechanism. For the isotropic Nb system at 3 (K), a large mean-free path of L = 6.7 x 10(-2) (cm) and a diffusion coefficient of D = 2.5 x 10(5) (cm/s) were obtained. The base layer transit time was estimated to be about 0.3 (ps) for a 1000 (angstrom) thin Nb base at 3 (K). We also applied this method in the case of the oxide high-T(c) superconductor YBa2Cu3O7, by modifying the corresponding parameter value.