Decoherence Effects in a Three-Level System under Gaussian Process

Abstract

When subjected to a classical fluctuating field characterized by a Gaussian process, we examine the purity and coherence protection in a three-level quantum system. This symmetry of the three-level system is examined when the local random field is investigated further in the noiseless and noisy regimes. In particular, we consider fractional Gaussian, Gaussian, Ornstein–Uhlenbeck, and power law noisy regimes. We show that the destructive nature of the Ornstein–Uhlenbeck noise toward the symmetry of the qutrit to preserve encoded purity and coherence remains large. Our findings suggest that properly adjusting the noisy parameters to specifically provided values can facilitate optimal extended purity and coherence survival. Non-vanishing terms appear in the final density matrix of the single qutrit system, indicating that it is in a strong coherence regime. Because of all of the Gaussian noises, monotonic decay with no revivals has been observed in the single qutrit system. In terms of coherence and information preservation, we find that the current qutrit system outperforms systems with multiple qubits or qutrits using purity and von Neumann entropy. A comparison of noisy and noiseless situations shows that the fluctuating nature of the local random fields is ultimately lost when influenced using the classical Gaussian noises.

Probing multipartite entanglement, coherence and quantum information preservation under classical Ornstein–Uhlenbeck noise

“…The ORU technique is a static Gaussian-Markov operation, and is characterized by ORU noise, demonstrated as one of the abundant and root causes of the information, coherence and quantum correlations losses in many quantum mechanical protocols [34][35][36][37][38][39][40]. ORU noise has been extensively studied in the case of two-qubit, three qubits, single qutrit and hybrid qubit-qutrit states and we find that in each case, the degree and behaviour of losses are different [41][42][43][44]. In the present situation, we impose the ORU noise on the dynamical map of the four-qubit GHZ-state, which is initially prepared in the state ρ o with p set to unity.…”

Multistage entanglement swapping using superconducting qubits in the absence and presence of dissipative environment without Bell state measurement

“…Quantum systems that have never interacted can be entangled through an entanglement swapping protocol 1 – 6 . The protocol of entanglement swapping is an essential tool for quantum communication 7 .…”