"Quantum physics, when applied to computing, is projected to lead to revolutionary enhancements in computational speed and power. However, to construct such a "quantum" computer, its building blocks, called qubits, have to be resistant to environmental disturbance; they need to hold the information encoded within them for long periods. One of the most promising ways to create such qubits consists in exploiting the spin degree of freedom of natural atoms implanted in silicon.
This project proposes to investigate the coherent manipulation of a single door electron spin coupled to a charge detector.
For this purpose, we will develop a new technique to determine the spin state of a single donor, relying on a spin-to-charge conversion induced by bound-exciton optical transitions. This method shows several advantages: it can work up to 4K, and at low magnetic field. It has been successfully implemented on assembly but never at the single donor level.
The final experiment of this project will comprise two steps: i) the manipulation of the spin information using microwave excitations in order to create superposition of states ii) and the reading of the spin information using an optoelectronic detection scheme, which is at the centre of this project."