2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/147566We calculate the admittance of a two-dimensional quantum point contact (QPC) using a Boltzman-like kinetic equation derived for a partial Wigner distribution function in an effective potential. We show that this approach leads to the known stepwise behavior of the admittance as a function of the gate voltage. The emittance contains both a quantum inductance determined by the harmonic mean of the velocities for the propagating electron modes and a quantum capacitance determined by the reflected modes.4 pages (Revtex), 2 figures, submitted to PRLCondensed Mattertext