On decoherence induced by a spin chain: role of initial prepared states

TL;DR

This paper investigates how the initial state of a spin chain environment influences decoherence of a central spin and quantum correlations, revealing that initial states, coupling strength, and proximity to quantum critical points significantly affect decoherence dynamics.

Contribution

It provides a heuristic analysis of decoherence induced by different initial states of a spin chain environment, highlighting the role of physical parameters and initial state choices.

Findings

Decoherence is suppressed in the vacuum state at strong coupling.

Oscillatory decoherence occurs when starting from the ground state.

Quantum correlations are protected when the environment is in a W state.

Abstract

We study the decoherence process induced by a spin chain environment on a central spin consisting of R spins and we apply it on the dynamics of quantum correlations (QCs) of three interacting qubits. In order to see the impact of the initial prepared state of the spin chain environment on the decoherence process, we assume the spin chain environment prepared in two main ways, namely, either the ground state or the vacuum state in the momentum space. We develop a general heuristic analysis when the spin chain environment in prepared in these states, in order to understand the decoherence process against the physical parameters. We show that the decoherence process is mainly determined by the choice of the initial prepared state, the number of spin of the chain, the coupling strength, the anisotropy parameter and the position from the quantum critical point. In fact, in the strong coupling regime, the decoherence process does not appear for the environment prepared in the vacuum state and it behaves oscillatory in the case of evolution from ground state. On the other hand, in the weak coupling regime and far from the quantum critical point, decoherence induced by the ground state is weaker than that of the vacuum state. Finally, we show that, QCs are completely shielded from decoherence in the case of evolution from the W state and obey the same dynamics as the decoherence factors for the GHZ state.