  The memory effects in non-Markovian quantum dynamics can induce the revival
of quantum coherence, which is believed to provide important physical resources
for quantum information processing (QIP). However, no real quantum algorithms
have been demonstrated with the help of such memory effects. Here, we
experimentally implemented a non-Markovianity-assisted highfidelity refined
Deutsch-Jozsa algorithm (RDJA) with a solid spin in diamond. The memory effects
can induce pronounced nonmonotonic variations in the RDJA results, which were
confirmed to follow a non-Markovian quantum process by measuring the
non-Markovianity of the spin system. By applying the memory effects as physical
resources with the assistance of dynamical decoupling, the probability of
success of RDJA was elevated above 97% in the open quantum system. This study
not only demonstrates that the non-Markovianity is an important physical
resource but also presents a feasible way to employ this physical resource. It
will stimulate the application of the memory effects in non-Markovian quantum
dynamics to improve the performance of practical QIP.

Quantum Physics