  In semiconductor electronics, the field-effect refers to the control of
electrical conductivity in nanoscale devices, which underpins the field-effect
transistor, one of the cornerstones of present-day semiconductor technology.
The effect is enabled by the penetration of the electric field far into a
weakly doped semiconductor, whose charge density is not sufficient to screen
the field. On the contrary, the charge density in metals and superconductors is
so large that the field decays exponentially from the surface and can penetrate
only a short distance into the material. Hence, the field-effect should not
exist in such materials. Nonetheless, recent publications have reported
observation of the field-effect in superconductors and proximised normal metal
nanodevices. The effect was discovered in gated nanoscale superconducting
constrictions as a suppression of the critical current under the application of
intense electric field and interpreted in terms of an electric-field induced
perturbation propagating inside the superconducting film. Here we show that
ours, and previously reported observations, governed by the overheating of the
constriction, without recourse to novel physics. The origin of the overheating
is a leakage current between the gate and the constriction, which perfectly
follows the Fowler-Nordheim model of electron field emission from a metal
electrode.c`
