Multi-charge pumping at 1GHz with a hybrid metal/semiconductor device

We present a new electron pump based on a metallic (NiSi) nanowire and two short silicon transistors acting as tunable barriers. Several electrons are pumped at high frequency and zero bias with a scheme where a controlled number of Coulomb segments are enclosed. The record current of 1.12 nA is produced at 0.6K and 1 GHz with 7 electrons per cycle (I=7ef). The devices are robust, mass-produced and can be integrated with on-chip silicon electronics to build a practical standard.