A fraction Td/N of the current GV injected through the first point contact by the current source is directly transmitted through the second point contact (and then drained to ground). Here G = (2e2/h)N is the conductance of the individual point contact, and V is the source-drain voltage. The remaining fraction 1 − Td/N equilibrates in the region between the point contacts, as a result of inelastic scattering