Single- and few-electron dynamic quantum dots in a perpendicular magnetic field

We present experimental studies of the current pumped through a dynamic quantum dot over a wide range of magnetic fields. At low fields we observe a repeatable structure indicating increased confinement of the electrons in the dynamic dot. At higher fields (B > 5T), we observe a structure which changes markedly from device to device suggesting that in this regime the transport is sensitive to local disorder. The results are significant for the development of dynamic quantum dot pumps as quantum standards of electrical current. (C) 2011 American Institute of Physics. [doi :10.1063/1.3578685]