Abstract

The structure of a multiplexed charge-locking system is introduced, together with its operation to deplete electrons on the measuring 2DEG. This device has the advantage of enabling independent control over a considerable number of gates with limited electrical contacts. Preliminary tests for these devices have been carried out at 4.2 K and the results are presented. It was reaffirmed (with reference to previous measurements [1]) that the current through the measuring 2DEG would drift in time even though the charge on the gate on top of it was locked. It was also found that the drift behavior was related to the history of how this current had been pinched-off (through the use of the top gates). An intrinsic charge leaking was observed from a charge-locked gate when some of the other gates was addressed. New designs have been brought forward aiming to tackle the above two problems. The prospective applications of this device is briefly discussed.

[1] R. K. Puddy et al, arXiv: cond-mat/1408.2872v2 (2014)