Unidirectional currents in asymmetric nanojunctions and electronic wavepacket interference

In recent few years, ultrafast electron emission from gold dimer nanoantennas (nanojunctions) with gap sizes down to few nanometers has attracted great interest for on-chip electronics, promising petahertz signal processing bandwidth [2] , [3] . When embedding such a nanojunction into a closed circuit, unidirectional currents bursts which vary on the sub-cycle scale, may arise [2] - [5] . Such currents can be created in symmetric structures driven by few- cycle pulses affected by carrier envelope phase (CEP) control [2] , [3] , or alternatively, in asymmetric nanostructures [4] , [5] (see Fig. 1a,b ). In the last case, CEP control is not needed.