A MEMORY DEVICE AND A MEMORY ARRAY

摘要

A memory has at least one memory device (1) having an input region (3) for carrying a current, an output region (4) for carrying a current, and a three-dimensionally confined quantum region (2a) arranged to operate in the coulomb blockade regime and separating the input and output regions (3 and 4) whereby charge carriers can only pass from the input region to the output region by tunnelling through the quantum region (4). A magnetic field (Bdc) is used to control Zeeman splitting in the memory device such that the input and output regions (3 and 4) are spin polarised whereby conduction through the input and output regions is by charge carriers of one spin polarity. In one arrangement, a pulsed AC magnetic field (Bac) is used to control the spin polarisation of an uppermost charge carrier in the quantum region to control the tunnelling current through the memory device. In another arrangement the polarisation of the magnetic field applied to the output region is used to switch the memory device between a conducting and a non-conducting state so that the memory device acts as a current switch.