Anti-symmetry consideration on the preservation of Entanglement of spin system

TL;DR

This paper introduces a method leveraging anti-symmetric properties of the Hamiltonian to reversibly control and protect entanglement in multi-qubit spin systems, especially in a three-spin Ising chain, with potential broader applicability.

Contribution

It presents a novel control technique based on Hamiltonian anti-symmetry to preserve entanglement in spin systems over long times and for arbitrary initial states.

Findings

Effective entanglement protection over long times

Control of both multiparty and pairwise entanglement

Applicable to general n-qubit spin models

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 an 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.