Shot noise measurements in a wide-channel transistor near pinch-off
V. S. Khrapai, D. V. Shovkun
Institute of Solid State Physics RAS, 142432 Chernogolovka, Russian Federation
We study a shot noise of a wide channel gated
high-frequency transistor at temperature of 4.2 K near pinch-off.
In this regime, a transition from the metallic to the insulating
state is expected to occur, accompanied by the increase of the
partition noise. The dependence of the noise spectral density on
current is found to be slightly nonlinear. At low currents, the
differential Fano factor is enhanced compared to the universal
value 1/3 for metallic diffusive conductors. We explain this
result by the effect of thermal fluctuations in a nonlinear regime
near pinch-off, without calling for the enhanced partition noise.