Electron-spin-resonance transistors for quantum computing in silicon-germanium heterostructures - art. no. 012306

We apply the full power of modem electronic band-structure engineering and epitaxial heterostructures to design a transistor that can sense and contro l a single-donor electron spin. Spin-resonance transistors may form the tec hnological basis for quantum information processing. One- and two-qubit ope rations are performed by applying a gate bias. The bias electric field pull s the electron wave function away from the dopant ion into layers of differ ent alloy composition. Owing to the variation of the g factor (Si:g = 1.998 ,Ge:g = 1.563), this displacement changes the spin Zeeman energy, allowing single-qubit operations. By displacing the electron even further, the overl ap with neighboring qubits is affected, which allows two-qubit operations. Certain silicon-germanium alloys allow a qubit spacing as large as 200 nm, which is well within the capabilities of current lithographic techniques. W e discuss manufacturing limitations and issues regarding scaling up to a la rge size computer.