Entanglement protection in higher-dimensional systems

Abstract

The inevitable dissipative interaction of an entangled quantum system with its environment causes degradation in quantum correlations present in the system. This can lead to a finite-time disappearance of entanglement, which is known as Entanglement Sudden Death (ESD). Here, we consider an initially entangled qubit-qutrit system and a dissipative noise which leads to ESD, and propose a set of local unitary operations, which when applied on the qubit, qutrit, or both subsystems during the decoherence process, cause ESD to be hastened, delayed, or avoided altogether, depending on its time of application. Delay and avoidance of ESD may find practical application in quantum information processing protocols that would otherwise suffer due to short lifetime of entanglement. The physical implementation of these local unitaries is discussed in the context of an atomic system. The simulation results of such ESD manipulations are presented for two different classes of initially entangled qubit-qutrit systems. A prescription for generalization of this scheme to a qutrit-qutrit system is given. This technique for entanglement protection in the noisy environment is compared with other related techniques such as weak measurement reversal, dynamic decoupling, and quantum Zeno effect.

Postponing entanglement sudden death by quantum interferences

“…Extensive research has explored the phenomenon of ESD in qubitqutrit systems under various noise channels [63][64][65][66]. Additionally, recent studies have focused on investigating the preservation of entanglement in higher-dimensional systems [67]. In our work, we are focussing on the effect of VIC on prolonging entanglement in the qubit-qutrit system.…”

Postponing the decay of entanglement and quantum coherence for maximally entangled mixed states under the action of correlated noise channels

“…Numerous studies have examined the measures of entanglement and coherence to acquire deep knowledge of the decoherence mechanism in an open quantum system. Several methods have been proposed and experimentally demonstrated to protect entanglement from decoherence, such as quantum measurement reversal (Korotkov10 and Keane, 2010), using local unitary operations (Singh et al, 2017;Singh, 2022;Singh and Sinha, 2022), feedback control (Doherty et al, 2000), and quantum Zeno effect (Itano et al, 1990). It is always interesting to find new methods (Merkli et al, 2012) to protect entanglement and coherence from the detrimental effects of the environment.…”