Suppression of Decoherence and Disentanglement by the Exchange Interaction

Abstract

Entangled qubit pairs can serve as a quantum memory or as a resource for quantum communication. The utility of such pairs is measured by how long they take to disentangle or decohere. To answer the question of whether qubit-qubit interactions can prolong entanglement, we calculate the dissipative dynamics of a pair of qubits coupled via the exchange interaction in the presence of random telegraph noise and $1/f$ noise. We show that for maximally entangled (Bell) states, the exchange interaction generally suppresses decoherence and disentanglement. This suppression is more apparent for random telegraph noise if the noise is non-Markovian, whereas for $1/f$ noise the exchange interaction should be comparable in magnitude to strongest noise source. The entangled singlet-triplet superposition state of 2 qubits (${\psi }_{\pm }$ Bell state) can be protected by the interaction, while for the triplet-triplet state (${\varphi }_{\pm }$ Bell state), it is less effective. Thus the former is more suitable for encoding quantum information.

References in corpus (11)

• Fault-Tolerant Quantum Dynamical Decoupling
• Protecting entanglement via the quantum Zeno effect
• Theory of electron spin decoherence by interacting nuclear spins in a quantum dot
• Entanglement dynamics of two independent qubits in environments with and without memory
• 1/f Flux Noise in Josephson Phase Qubits
• Low-frequency noise as a source of dephasing of a qubit
• Towards Fault Tolerant Adiabatic Quantum Computation
• Universal pulse sequence to minimize spin dephasing in the central spin decoherence problem
• High-fidelity gates in a Josephson qubit
• Telegraph Noise in Coupled Quantum Dot Circuits Induced by a Quantum Point Contact
• Exact solution of a model of qubit dephasing due to telegraph noise

Cited by in corpus (17)

• 1/f noise: implications for solid-state quantum information
• Dynamics of quantum correlations in colored environments
• Time-evolution of tripartite quantum discord and entanglement under local and non-local random telegraph noise
• Nonperturbative Leakage Elimination Operators and Control of a Three-Level System
• Effect of Markov and Non-Markov Classical Noise on Entanglement Dynamics
• Inverse Engineering Control in Open Quantum Systems
• Non-Perturbative Quantum Dynamical Decoupling
• Control relaxation via dephasing: an exact quantum state diffusion study
• The dynamics of two entangled qubits exposed to classical noise: role of spatial and temporal noise correlations
• Environmental noise effects on entanglement fidelity of exchange-coupled semiconductor spin qubits
• Quantum correlations of identical particles subject to classical environmental noise
• Topology of Entanglement Evolution of Two Qubits
• Phenomenological noise model for superconducting qubits: two-state fluctuators and 1=f noise
• Magnetization Noise Induced Collapse and Revival of Rabi Oscillations in circuit QED
• 1/f Flux Noise in low-T${}_c$ SQUIDs due to Superparamagnetic Phase Transitions in Defect Clusters
• Interplay between nonclassicality and $\mathcal{P}\mathcal{T}$ symmetry in an effective two level system with open system effects
• Disappearance of entanglement: a topological point of view