Patent ID: 8735964

Claim:
An apparatus comprising: an insulating region; a semiconductor region adjacent to the insulating region; an array of impurity ions disposed in the insulating region at a predetermined distance from the semiconductor region; an array of electrometers arranged to detect whether at least one charge carrier in the semiconductor region is bound to a respective impurity ion; an array of sets of at least one control gate, each set associated with a respective electrometer, each at least one control gate-being configured to apply an electric field to the insulating region and semiconductor region for controlling binding of at least one charge carrier to a respective impurity ion; wherein each at least one control gate is configured to be operable to cause at least one charge carrier in the semiconductor region to bind to a respective impurity-ion in response to applied an bias and wherein the impurity ions are arranged in the insulating layer and are separated from the semiconductor region by the predetermined distance such that the at least one charge carrier and the impurity ion bind at the applied bias without the at least one charge carrier leaving the semiconductor region and remain bound when the applied bias is removed.