Geometric single-qubit gates for an electron spin in a quantum dot

Using the analytic expression of the evolution operator for the electron spin in a quantum dot, we propose a scheme to design a universal set of single-qubit gates based solely on the geometric phase that the qubit state acquires after a cyclic evolution in the parameter space. The scheme is using ultrafast linearly chirped pulses providing adiabatic excitation of the qubit states and the geometric phase is fully controlled by the relative phase between pulses. (C) 2012 Wiley Periodicals, Inc.