Universal protection of unitary evolution from slow noise: dynamical control pushed to the extreme

G. Bensky, E. Brion, F. Carlier, V. M. Akulin, G. Kurizki

Published 2009-05-20Version 1

We propose a technique that allows to simultaneously perform universal control of the evolution operator and compensate for the first order contribution of an arbitrary Hermitian constant noise. We show that, at least, a three-valued Hamiltonian is needed in order to protect the system against any such noise. This technique is illystrated by an explicit algorithm for a control sequence that is applied to numerically design a safe two-qubit gate.