Bunching and anti-bunching in electronic transport
  In quantum optics the $g^{(2)}$-function is a standard tool to investigate photon emission statistics. We define a $g^{(2)}$-function for electronic transport and use it to investigate the bunching and anti-bunching of electron currents. Importantly, we show that super-Poissonian electron statistics do not necessarily imply electron bunching, and that sub-Poissonian statistics do not imply anti-bunching. We discuss the information contained in $g^{(2)}(\tau)$ for several typical examples of transport through nano-structures such as few-level quantum dots. 
Clive Emary, Christina P\"oltl, Alexander Carmele, Julia Kabuss,   Andreas Knorr, and Tobias Brandes
cond-mat.mes-hall quant-ph