A semiconductor stack for performing at least a logic operation includes adjacent layers arranged in a stacked configuration with each layer comprising at least a phase-change memory cell in which a phase-change material is provided between a heater electrical terminal and at least two further heater electrical terminals, the phase-change material between the heater electrical terminal and each of the two further heater electrical terminals being operable in one of at least two reversibly transformable phases, an amorphous phase and a crystalline phase; wherein the semiconductor stack, when in use, is configurable to store information by way of an electrical resistance of the phase of the phase-change material between each heater electrical terminal and each of the two further heater electrical terminals in each layer, and the logic operation is performed on the basis of the information stored in the adjacent layers.