Universal protection of unitary evolution from slow noise: dynamical control pushed to the extreme
Guy Bensky, E. Brion, F. Carlier, V. M. Akulin, Gershon Kurizki · arXiv (Cornell University) · 2009
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.