One-spin quantum logic gates from exchange interactions and a global magnetic field

Abstract

It has been widely assumed that one-qubit gates in spin-based quantum computers suffer from severe technical difficulties. We show that one-qubit gates can in fact be generated using only modest and presently feasible technological requirements. Our solution uses only global magnetic fields and controllable Heisenberg exchange interactions, thus circumventing the need for single-spin addressing.Comment: 4 pages, incl. 1 figure. This significantly modified version accepted for publication in Phys. Rev. Let