Adiabatic quantum pump in a zigzag graphene nanoribbon junction*
Zhang Lin
       
Schematic diagram of an adiabatic quantum pump based on a ZGNR junction. The middle C region is an un-doped ZGNR with two time-dependent pumping fields u 1( t ) and u 2( t ) asymmetrically applied on the boundaries P1 and P2, respectively. The left (L) and the right (R) ZGNRs are two semi-infinite p(n)-doped or ferromagnetic leads with two controllable gate voltages U L and U R. The width of the ZGNR is described by the zigzag-chain number N , and the length of the C region is denoted by LN .