|
Abstract
|
In this work we offer an approach to protect the entanglement
based on the anti-symmetric property of the Hamiltonian. Our
main objective is to protect the entanglement of a given initial
three-qubit state which is governed by Hamiltonian of a three-spin
Ising chain in site-dependent transverse fields. We show that according
to anti-symmetric property of the Hamiltonian with respect
to some operators mimicking the time reversal operator, the
dynamics of the system can be effectively reversed. It equips us to
control the dynamics of the system. The control procedure is implemented
as a sequence of cyclic evolution; accordingly the entanglement
of the system is protected for any given initial state with any
desired accuracy and long-time. Using this approach we could control
not only the multiparty entanglement but also the pairwise entanglement.
It is also notable that in this paper although we restrict
ourselves mostly within a three-spin Ising chain in site-dependent
transverse fields, our approach could be applicable to any n-qubit
spin system models.
|