Arithmetic logic unit of a computer based on spin-polarised single electrons

The design of an arithmetic logic unit (ALU) is presented using ‘single spin logic’ where classical binary bits 0 and 1 are encoded in orthogonal spin polarisations of single electrons hosted in semiconductor quantum dots. The logic signal (spin state) is transmitted from one spin to the next via nearest-neighbour exchange interaction. The ALU circuits are implemented by placing the quantum dots in specific geometric patterns on a wafer so as to realise the desired relationships between the input and output spin states.