Wavefunction Engineering of Individual Donors for Silicon-Based Quantum Computers

摘要

This project has explored possibilities for realizing a Kane-type quantum computer based on Si:P donor qubits. The overall goal has been to create an integrated process based on STM patterning of individual P-donor qubits, combined with single-electron transistors (SETs) for singlet-triplet spin state detection in the same lithographic step. The main accomplishments during this period have been to: (1) develop processes for positioning P atom donors and self-ordered arrays with near-atomic accuracy inside the silicon crystal lattice, (2) fabricate P donor nanowires as a major step toward an integrated epitaxial single-electron transistor, (3) measure electrical characteristics of the unpatterned P delta-layer and P donor nanowires, (4) compare the electrical data with our band structure calculations on the P delta- layer and previous theories of weak localization, (5) propose a new Kane-type architecture employing the idea of 'universal exchange' based on composite 3- electron spin qubits, and (6) perform extensive simulations to confirm the fundamental aspects of this approach, and quantify major difficulties to be overcome. Sustained effort in these directions will be required to realize a working qubit.