2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27254Numerical simulations of conduction through a disordered microbridge between a normal metal and a superconductor have revealed an anomalous insensitivity of the conductance fluctuations to a magnetic field. A theory for the anomaly is presented: Both an exact analytical calculation (using random-matrix theory) and a qualitative symmetry argument (involving the exchange of time-reversal for reflection symmetry).8 pages, REVTeX-3.0, 2 figuresCondensed Mattertext