Transport through quantum dots: A supersymmetry approach to transmission eigenvalue statistics

We study quantum transport through ballistic cavities coupled to two electr on reservoirs by point contacts. We develop a powerful method, based on sup ersymmetry, to calculate exactly transmission eigenvalue statistics in the presence of tunnel barriers and for a small number of open scattering chann els. We calculate the transmission eigenvalue density for ballistic point c ontacts and find it to be consistent with a distribution of transmission ei genvalues given by the Jacobi ensemble from random-matrix theory. We also c alculate explicitly the transmission eigenvalue density for quantum dots wi th tunneling point contacts. [S0163-1829(98)51044-2].