Y. Hiraki et al., SPATIAL VARIATION OF LOCAL CURRENT NOISE DUE TO IMPURITY SCATTERING AND LOCAL CHARGE-INDUCED NOISE, JPN J A P 1, 34(8B), 1995, pp. 4365-4368
We analyze the noise characteristics associated with the fluctuation o
f the number of electrons in two terminal elements. We find that the l
ocal current noise on leads around a point contact varies spatially. T
he local current noise resulting; from short wavelength fluctuations d
iffers from the standard one resulting from long wavelength fluctuatio
ns. The excess shot noise near the point contact decreases towards the
leads, and the characteristic length is the mean free path of electro
ns l. At distances longer than l from the contact, the local noise app
roaches the pure thermal noise given by 4k(B)TG(Q) with the quantized
conductance G(Q). We also find that the tunneling current of resonant
tunneling devices (RTDs) is strongly influenced by the existence of th
e immobile charges captured by the localized traps. By treating the el
ectron capture and emission processes kinematically, we simulate rando
m telegraph noise (RTN).