▁bar rier ▁di ode , ▁it ▁is ▁, ▁, ▁where ▁ ▁is ▁the ▁Bol tz mann ▁constant , ▁T ▁the ▁absolute ▁temperature , ▁v ▁the ▁voltage ▁and ▁ ▁the ▁total ▁current . ▁In ▁particular , ▁for ▁ ▁the ▁conduct ance ▁becomes ▁ ▁and ▁the ▁above ▁equation ▁gives ▁▁ ▁, ▁ ▁that ▁is ▁the ▁thermal ▁noise ▁at ▁thermal ▁equilibrium ▁given ▁by ▁the ▁Ny qu ist ▁theorem . ▁If ▁the ▁car rier ▁mot ions ▁are ▁correl ated , ▁the ▁above ▁equation ▁has ▁to ▁be ▁changed ▁to ▁the ▁form ▁( for ▁) ▁▁ ▁, ▁ ▁where ▁ ▁is ▁the ▁so - called ▁F ano ▁factor ▁that ▁can ▁be ▁both ▁less ▁than ▁ 1 ▁( for ▁instance ▁in ▁the ▁case ▁of ▁car rier ▁generation - re com bin ation ▁in ▁non ide al ▁p n ▁j unction s ), ▁and ▁greater ▁than ▁ 1 ▁( as ▁in ▁the ▁negative ▁resistance ▁region ▁of ▁reson ant - t unn eling ▁di ode , ▁as ▁a ▁result ▁of ▁the ▁electron - elect ron ▁interaction ▁being ▁en hanced ▁by ▁the ▁particular ▁shape ▁of ▁the ▁density ▁of ▁states ▁in ▁the ▁well .) ▁ ▁Th erm al ▁noise ▁ ▁Once ▁again ▁from ▁the ▁cor pus cular ▁point ▁of ▁view , ▁let ▁us ▁evaluate ▁the ▁thermal ▁noise ▁with ▁the ▁aut oc or relation ▁function ▁ ▁of ▁ ▁by ▁means ▁of ▁the ▁second ▁term ▁of ▁the ▁second ▁equation ▁of ▁section ▁Fl uct u ations , ▁that ▁for ▁the ▁short ▁circuit ▁condition ▁ ▁( i . e ., ▁at ▁thermal ▁equilibrium ) ▁which ▁implies ▁, ▁becomes