Statistical study and parallelization of multiplexed single-electron sources

Increasing the electric current from a single-electron source is a main challenge in an effort to establish the standard of the ampere defined by the fixed value of the elementary charge e and the operation frequency f. While the current scales with the frequency, due to an operation frequency limit for maintaining accurate single-electron transfer, parallelization of single-electron sources is expected to be a more practical solution to increase the generated electric current I=Nef, where N is the number of parallelized devices. One way to parallelize single-electron sources without increasing the complexity in device operation is to use a common gate. Such a scheme will require each device to have the same operation parameters for single-electron transfer. In order to investigate this possibility, we study the statistics for operation gate voltages using single-electron sources embedded in a multiplexer circuit. The multiplexer circuit allows us to measure 64 single-electron sources individually in a single cooldown. We also demonstrate the parallelization of three single-electron sources and observe the generated current enhanced by a factor of three.