Quantum Bang-Bang control of entangle states

TL;DR

This paper investigates how quantum Bang-Bang control techniques can preserve and revive entanglement in a two-qubit system interacting with an environment, preventing entanglement loss and sudden death.

Contribution

It demonstrates that pulsed control can maintain and restore entanglement in entangled qubits affected by environmental interactions.

Findings

Pulsed control preserves entanglement against environmental decoherence.

A single pulse can revive entanglement after sudden death.

Control techniques can mitigate entanglement loss in quantum systems.

Abstract

The effect of quantum "Bang-Bang" control on entangled states is studied. A system of two initially entangled qubits interacting with a bosonic environment is considered. The interaction induces a loss of the initial entanglement of the two qubits and for specific initial states it causes "entanglement sudden death". A pulsed control of both qubits leads to the preservation of the entanglement. It is also shown that a single pulse performed after the sudden death time induces an entanglement revival in the two qubits system.