Decoherence from a spin-chain with three-site interaction

TL;DR

This paper studies how quantum correlations like discord and entanglement evolve over time in a two-qubit system coupled to a spin chain with three-site interactions, revealing conditions that delay their decay and phenomena like sudden transitions.

Contribution

It uncovers specific intervals of three-site coupling strength that delay quantum correlation decay and observes the impact of anisotropy on transition times.

Findings

Quantum correlations decay rapidly at the critical point.

Certain three-site coupling intervals delay decay of discord and entanglement.

Transition times between classical and quantum decoherence can be controlled.

Abstract

We investigate the time evolution of quantum discord and entanglement for two-qubit coupled to a spin chain with three-site interaction in the weak-coupling region. If the quantum system evolves from a Bell state, quantum correlations decay to zero in a very short time at the critical point of the environment. We found there exist some special interval of the three-site coupling strength in which the decay of quantum discord and entanglement can be delayed. When the qubits are initially prepared in a Bell diagonal state, the decay of entanglement is also delayed in the special interval, but the decay of quantum discord is enhanced. Besides, the sudden transition between classical and quantum decoherence is observed. we found the transition time can be lengthened at the special range of three-site interaction and shorten by degree of anisotropy.