Non-Markovian Effect and Control of Quantum Information
by
Chikako Uchiyama
University of Yamanashi
Coauthors: Masaki Aihara (Nara Institute of Science and Technology)

It is known that the "bang-bang" method is effective to suppress the decoherence caused by the interaction between qubit and environment. Conventionally, the degree of suppression is discussed in the limit of extremely short pulse interval. Since this condition is difficult to execute in experimental settings, we will propose a strategy where the condition for the pulse interval can be released by paying attention to the dynamical behavior of the environment. We find that the coherence can be periodically recovered by synchronizing pulse interval with the dynamical motion of the reservoir. This is because that the non-Markovian property of the system (memory effect of environment) is the physical background of the suppression of decoherence by synchronized multipulse application. We will show that we can extend this strategy to control disentanglement.

Date received: April 1, 2004